Sometimes, two heads are NOT as good as one. (#170)

Check whether the current user has access to KVM before attempting to add udev rule

.github/workflows/ci.yml

@@ -11,9 +11,9 @@ jobs:
     runs-on: ubuntu-22.04
     needs:
       - check-dist-up-to-date
-      - install-nix-linux
-      - install-nix-macos
+      - install-nix
       - install-with-non-default-source-inputs
+      - install-no-id-token
     # NOTE(cole-h): GitHub treats "skipped" as "OK" for the purposes of required checks on branch
     # protection, so we take advantage of this fact and fail if any of the dependent actions failed,
     # or "skip" (which is a success for GHA's purposes) if none of them did.
@@ -28,7 +28,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@main
-      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - uses: DeterminateSystems/flakehub-cache-action@main
       - name: pnpm install
         run: nix develop --command pnpm install
       - name: prettier format
@@ -44,14 +44,22 @@ jobs:
       - name: Ensure no staged changes
         run: git diff --exit-code
 
-  install-nix-linux:
-    name: Run test suite for Linux systems
+  install-nix:
+    name: "Test: ${{ matrix.runner }}${{ matrix.determinate && ' with determinate' || '' }}"
     strategy:
+      fail-fast: false
       matrix:
         runner:
           - ubuntu-latest
           - nscloud-ubuntu-22.04-amd64-4x16
           - namespace-profile-default-arm64
+          # - macos-12-large # determinate-nixd is broken on macos-12
+          - macos-13-large
+          - macos-14-large
+          - macos-14-xlarge # arm64
+        determinate:
+          - true
+          - false
     runs-on: ${{ matrix.runner }}
     permissions:
       contents: read
@@ -65,6 +73,7 @@ jobs:
           log-directives: nix_installer=trace
           backtrace: full
           _internal-strict-mode: true
+          determinate: ${{ matrix.determinate }}
       - name: echo $PATH
         run: echo $PATH
 
@@ -82,91 +91,6 @@ jobs:
           nix store gc
           nix run nixpkgs#hello
 
-      - name: Test bash
-        run: nix-instantiate -E 'builtins.currentTime' --eval
-        if: success() || failure()
-        shell: bash --login {0}
-      - name: Test sh
-        run: nix-instantiate -E 'builtins.currentTime' --eval
-        if: success() || failure()
-        shell: sh -l {0}
-      - name: Install Nix again (noop)
-        uses: ./
-        with:
-          logger: pretty
-          log-directives: nix_installer=trace
-          backtrace: full
-          _internal-strict-mode: true
-      - name: Test `nix` with `$GITHUB_PATH`
-        if: success() || failure()
-        run: |
-          nix run nixpkgs#hello
-          nix profile install nixpkgs#hello
-          hello
-          nix store gc
-          nix run nixpkgs#hello
-      - name: Reinstall Nix
-        uses: ./
-        with:
-          logger: pretty
-          log-directives: nix_installer=trace
-          backtrace: full
-          reinstall: true
-          extra-conf: |
-            use-sqlite-wal = true
-          _internal-strict-mode: true
-      - name: Test `nix` with `$GITHUB_PATH`
-        if: success() || failure()
-        run: |
-          nix run nixpkgs#hello
-          nix profile install nixpkgs#hello
-          hello
-          nix store gc
-          nix run nixpkgs#hello
-      - name: Verify the generated nix.conf
-        run: |
-          cat -n /etc/nix/nix.conf
-          grep -E "^trusted-users = .*$USER" /etc/nix/nix.conf
-          grep -E "^use-sqlite-wal = true" /etc/nix/nix.conf
-      - name: Breakpoint if tests failed
-        if: failure()
-        uses: namespacelabs/breakpoint-action@v0
-        with:
-          duration: 5m
-          authorized-users: grahamc
-
-  install-nix-macos:
-    name: Run test suite for macOS systems
-    strategy:
-      matrix:
-        runner:
-          # x86_64-darwin
-          - macos-12
-          # aarch64-darwin
-          - macos-latest-xlarge
-    runs-on: ${{ matrix.runner }}
-    permissions:
-      contents: read
-      id-token: write
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Nix
-        uses: ./
-        with:
-          logger: pretty
-          log-directives: nix_installer=trace
-          backtrace: full
-          _internal-strict-mode: true
-      - name: echo $PATH
-        run: echo $PATH
-      - name: Test `nix` with `$GITHUB_PATH`
-        if: success() || failure()
-        run: |
-          nix run nixpkgs#hello
-          nix profile install nixpkgs#hello
-          hello
-          nix store gc
-          nix run nixpkgs#hello
       - name: Test bash
         run: nix-instantiate -E 'builtins.currentTime' --eval
         if: success() || failure()
@@ -176,9 +100,8 @@ jobs:
         if: success() || failure()
         shell: sh -l {0}
       - name: Test zsh
-        run: nix-instantiate -E 'builtins.currentTime' --eval
+        run: if (zsh --help > /dev/null); then zsh --login --interactive -c "nix-instantiate -E 'builtins.currentTime' --eval"; fi
         if: success() || failure()
-        shell: zsh --login --interactive {0}
       - name: Install Nix again (noop)
         uses: ./
         with:
@@ -186,6 +109,7 @@ jobs:
           log-directives: nix_installer=trace
           backtrace: full
           _internal-strict-mode: true
+          determinate: ${{ matrix.determinate }}
       - name: Test `nix` with `$GITHUB_PATH`
         if: success() || failure()
         run: |
@@ -204,6 +128,7 @@ jobs:
           extra-conf: |
             use-sqlite-wal = true
           _internal-strict-mode: true
+          determinate: ${{ matrix.determinate }}
       - name: Test `nix` with `$GITHUB_PATH`
         if: success() || failure()
         run: |
@@ -214,15 +139,10 @@ jobs:
           nix run nixpkgs#hello
       - name: Verify the generated nix.conf
         run: |
-          cat /etc/nix/nix.conf
-          grep -E "^trusted-users = .*$USER" /etc/nix/nix.conf
-          grep -E "^use-sqlite-wal = true" /etc/nix/nix.conf
-      - name: Breakpoint if tests failed
-        if: failure()
-        uses: namespacelabs/breakpoint-action@v0
-        with:
-          duration: 5m
-          authorized-users: grahamc
+          nix config show
+          cat -n /etc/nix/nix.conf
+          nix config show | grep -E "^trusted-users = .*$USER"
+          nix config show | grep -E "^use-sqlite-wal = true"
 
   install-with-non-default-source-inputs:
     name: Install Nix using non-default source-${{ matrix.inputs.key }}
@@ -248,3 +168,13 @@ jobs:
           _internal-strict-mode: true
       - name: Ensure that the expected Nix version ${{ matrix.inputs.nix-version }} is installed via alternative source-${{ matrix.inputs.key }}
         run: .github/verify-version.sh ${{ matrix.inputs.nix-version }}
+
+  install-no-id-token:
+    name: Install Nix without an ID token
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./
+        with:
+          _internal-strict-mode: true
+          determinate: true

CONTRIBUTING.md

@@ -1,3 +1,5 @@
 # Submitting Pull Requests
 
+Run `pnpm install` to install necessary JS tools.
+
 This action is based off https://github.com/actions/javascript-action. As part of your contributing flow you **must** run `npm run all` before we can merge.

README.md

@@ -34,7 +34,7 @@ jobs:
 
 ### With FlakeHub
 
-To fetch private flakes from FlakeHub, update the `permissions` block and pass `flakehub: true`:
+To fetch private flakes from FlakeHub and Nix builds from FlakeHub Cache, update the `permissions` block and pass `determinate: true`:
 
 ```yaml
 on:
@@ -53,7 +53,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@main
         with:
-          flakehub: true
+          determinate: true
       - run: nix build .
 ```
 
@@ -85,9 +85,10 @@ Differing from the upstream [Nix](https://github.com/NixOS/nix) installer script
 | Parameter               | Description                                                                                                                                                                                                                                                                    | Type                                       | Default                                                        |
 | :---------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------- | :------------------------------------------------------------- |
 | `backtrace`             | The setting for [`RUST_BACKTRACE`][backtrace]                                                                                                                                                                                                                                  | string                                     |                                                                |
+| `determinate`           | Whether to install [Determinate Nix](https://determinate.systems/enterprise) and log in to FlakeHub for private Flakes and binary caches.                                                                                                                                      | Boolean                                    | `false`                                                        |
 | `extra-args`            | Extra arguments to pass to the planner (prefer using structured `with:` arguments unless using a custom [planner]!)                                                                                                                                                            | string                                     |                                                                |
 | `extra-conf`            | Extra configuration lines for `/etc/nix/nix.conf` (includes `access-tokens` with `secrets.GITHUB_TOKEN` automatically if `github-token` is set)                                                                                                                                | string                                     |                                                                |
-| `flakehub`              | Log in to FlakeHub to pull private flakes using the GitHub Actions [JSON Web Token](https://jwt.io) (JWT), which is bound to the `api.flakehub.com` audience.                                                                                                                  | Boolean                                    | `false`                                                        |
+| `flakehub`              | Deprecated. Implies `determinate`.                                                                                                                                                                                                                                             | Boolean                                    | `false`                                                        |
 | `force-docker-shim`     | Force the use of Docker as a process supervisor. This setting is automatically enabled when necessary.                                                                                                                                                                         | Boolean                                    | `false`                                                        |
 | `github-token`          | A [GitHub token] for making authenticated requests (which have a higher rate-limit quota than unauthenticated requests)                                                                                                                                                        | string                                     | `${{ github.token }}`                                          |
 | `github-server-url`     | The URL for the GitHub server, to use with the `github-token` token. Defaults to the current GitHub server, supporting GitHub Enterprise Server automatically. Only change this value if the provided `github-token` is for a different GitHub server than the current server. | string                                     | `${{ github.server }}`                                         |

action.yml

@@ -7,6 +7,10 @@ inputs:
   backtrace:
     description: The setting for `RUST_BACKTRACE` (see https://doc.rust-lang.org/std/backtrace/index.html#environment-variables)
     required: false
+  determinate:
+    description: |
+      Whether to install [Determinate Nix](https://determinate.systems/enterprise) and log in to FlakeHub for private Flakes and binary caches.
+    default: false
   extra-args:
     description: Extra args to pass to the planner (prefer using structured `with:` arguments unless using a custom planner!)
     required: false
@@ -14,7 +18,7 @@ inputs:
     description: Extra configuration lines for `/etc/nix/nix.conf` (includes `access-tokens` with `secrets.GITHUB_TOKEN` automatically if `github-token` is set)
     required: false
   flakehub:
-    description: Automatically log in to your [FlakeHub](https://flakehub.com) account, for accessing private flakes.
+    description: Deprecated. Implies `determinate`.
     required: false
     default: false
   force-docker-shim:
@@ -30,6 +34,9 @@ inputs:
   init:
     description: "The init system to configure, requires `planner: linux-multi` (allowing the choice between `none` or `systemd`)"
     required: false
+  job-status:
+    description: The overall status of the job. Set automatically, for aggregate analysis of Nix stability.
+    default: ${{ job.status }}
   kvm:
     description: Automatically configure the GitHub Actions Runner for NixOS test supports, if the host supports it.
     required: false

package.json

@@ -11,7 +11,8 @@
     "check-fmt": "prettier --check .",
     "lint": "eslint src/**/*.ts",
     "package": "ncc build",
-    "all": "pnpm run format && pnpm run lint && pnpm run build && pnpm run package"
+    "test": "vitest --watch false",
+    "all": "pnpm run test && pnpm run format && pnpm run lint && pnpm run build && pnpm run package"
   },
   "repository": {
     "type": "git",
@@ -25,26 +26,27 @@
   },
   "homepage": "https://github.com/DeterminateSystems/nix-installer-action#readme",
   "dependencies": {
-    "@actions/core": "^1.10.1",
+    "@actions/core": "^1.11.1",
     "@actions/exec": "^1.1.1",
-    "@actions/github": "^5.1.1",
+    "@actions/github": "^6.0.0",
     "detsys-ts": "github:DeterminateSystems/detsys-ts",
-    "got": "^14.3.0",
-    "string-argv": "^0.3.2"
+    "got": "^14.4.7",
+    "string-argv": "^0.3.2",
+    "vitest": "^3.1.1"
   },
   "devDependencies": {
     "@trivago/prettier-plugin-sort-imports": "^4.3.0",
-    "@types/node": "^20.14.0",
+    "@types/node": "^20.17.30",
     "@types/uuid": "^9.0.8",
-    "@typescript-eslint/eslint-plugin": "^7.12.0",
-    "@vercel/ncc": "^0.38.1",
-    "eslint": "^8.57.0",
-    "eslint-import-resolver-typescript": "^3.6.1",
+    "@typescript-eslint/eslint-plugin": "^7.18.0",
+    "@vercel/ncc": "^0.38.3",
+    "eslint": "^8.57.1",
+    "eslint-import-resolver-typescript": "^3.10.0",
     "eslint-plugin-github": "^4.10.2",
-    "eslint-plugin-import": "^2.29.1",
-    "eslint-plugin-prettier": "^5.1.3",
-    "prettier": "^3.3.0",
-    "tsup": "^8.1.0",
-    "typescript": "^5.4.5"
+    "eslint-plugin-import": "^2.31.0",
+    "eslint-plugin-prettier": "^5.2.6",
+    "prettier": "^3.5.3",
+    "tsup": "^8.4.0",
+    "typescript": "^5.8.3"
   }
 }

src/annotate.ts

@@ -0,0 +1,66 @@
+import * as core from "@actions/core";
+
+import type { Fix, FixHashesOutputV1, Mismatch } from "./fixHashes.js";
+
+function prettyDerivation(derivation: string): string {
+  return derivation.replace(/\/nix\/store\/\w+-/, "").replace(/.drv$/, "");
+}
+
+function annotateSingle(
+  file: string,
+  line: number,
+  { derivation, replacement }: Mismatch,
+): void {
+  const pretty = prettyDerivation(derivation);
+  core.error(`To correct the hash mismatch for ${pretty}, use ${replacement}`, {
+    file,
+    startLine: line,
+  });
+}
+
+function annotateMultiple(
+  file: string,
+  { line, found, mismatches }: Fix,
+): void {
+  const matches = mismatches
+    .map(({ derivation, replacement }) => {
+      const pretty = prettyDerivation(derivation);
+      return `* For the derivation ${pretty}, use ${replacement}`;
+    })
+    .join("\n");
+
+  core.error(
+    `There are multiple replacements for the expression ${found}:\n${matches}`,
+    {
+      file,
+      startLine: line,
+    },
+  );
+}
+
+function annotate(file: string, fix: Fix): void {
+  if (fix.mismatches.length === 1) {
+    annotateSingle(file, fix.line, fix.mismatches[0]);
+  } else {
+    annotateMultiple(file, fix);
+  }
+}
+
+/**
+ * Annotates fixed-output derivation hash mismatches using GitHub Actions'
+ *
+ * @param output The output of `determinate-nixd fix hashes --json`
+ * @returns The number of annotations reported to the user
+ */
+export function annotateMismatches(output: FixHashesOutputV1): number {
+  let count = 0;
+
+  for (const { file, fixes } of output.files) {
+    for (const fix of fixes) {
+      annotate(file, fix);
+      count++;
+    }
+  }
+
+  return count;
+}

src/events.test.ts

@@ -0,0 +1,65 @@
+import { parseEvents, getRecentEvents } from "./events.js";
+import { expect, test } from "vitest";
+
+// Handy test for locally making sure you can fetch recent events:
+// eslint-disable-next-line no-constant-condition
+if (false) {
+  test("Parsing existing events", async () => {
+    expect(await getRecentEvents(new Date(Date.now() - 1000000))).toStrictEqual(
+      [{}],
+    );
+  });
+}
+
+test("Parsing existing events", () => {
+  const events = parseEvents([
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/m96zgji4fhi70s2zs6pq5pric6ch7p4h-stdenv-darwin.drv",
+      outputs: ["/nix/store/dalhfz3l75w4b4q06sxzqgb2wfydvkbv-stdenv-darwin"],
+      timing: null,
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv",
+      outputs: ["/nix/store/qwlgz5da3pfb53gqpgdmazaj9jczrnly-dep-1"],
+      timing: {
+        startTime: "2025-04-11T14:38:02Z",
+        stopTime: "2025-04-11T14:38:05Z",
+        durationSeconds: 3,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: "/nix/store/ykvbksjqrza2zpj6nkbycrdfwgfdpr8g-hash-mismatch-md5-base16.drv",
+      timing: {
+        startTime: "2025-04-11T14:36:44Z",
+        stopTime: "2025-04-11T14:36:44Z",
+        durationSeconds: 0,
+      },
+    },
+  ]);
+  expect(events).toStrictEqual([
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv",
+      timing: {
+        durationSeconds: 3,
+        startTime: new Date("2025-04-11T14:38:02Z"),
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: "/nix/store/ykvbksjqrza2zpj6nkbycrdfwgfdpr8g-hash-mismatch-md5-base16.drv",
+      timing: {
+        durationSeconds: 0,
+        startTime: new Date("2025-04-11T14:36:44Z"),
+      },
+    },
+  ]);
+});

src/events.ts

@@ -0,0 +1,71 @@
+import got from "got";
+
+export interface DEvent {
+  v: string;
+  c: string;
+  drv: string;
+  timing: {
+    startTime: Date;
+    durationSeconds: number;
+  };
+}
+
+export function parseEvents(data: unknown): DEvent[] {
+  if (!Array.isArray(data)) {
+    return [];
+  }
+
+  return data.flatMap((event) => {
+    if (
+      event.v === "1" &&
+      (event.c === "BuildFailureResponseEventV1" ||
+        event.c === "BuiltPathResponseEventV1") &&
+      Object.hasOwn(event, "drv") &&
+      typeof event.drv === "string" &&
+      Object.hasOwn(event, "timing") &&
+      typeof event.timing === "object" &&
+      event.timing !== null
+    ) {
+      const timing = event.timing as { [key: string]: unknown };
+
+      if (
+        Object.hasOwn(timing, "startTime") &&
+        typeof timing.startTime === "string" &&
+        Object.hasOwn(timing, "durationSeconds") &&
+        typeof timing.durationSeconds === "number"
+      ) {
+        const date = Date.parse(timing.startTime);
+        if (!Number.isNaN(date)) {
+          return [
+            {
+              v: event.v,
+              c: event.c,
+              drv: event.drv,
+              timing: {
+                startTime: new Date(date),
+                durationSeconds: timing.durationSeconds,
+              },
+            },
+          ];
+        }
+      }
+    }
+
+    return [];
+  });
+}
+
+export async function getRecentEvents(since: Date): Promise<DEvent[]> {
+  const queryParam = encodeURIComponent(since.toISOString());
+
+  const resp = await got
+    .get(
+      `http://unix:/nix/var/determinate/determinate-nixd.socket:/events/recent?since=${queryParam}`,
+      {
+        enableUnixSockets: true,
+      },
+    )
+    .json();
+
+  return parseEvents(resp);
+}

src/failuresummary.test.ts

@@ -0,0 +1,274 @@
+import { expect, test } from "vitest";
+import {
+  FailureSummary,
+  getBuildFailures,
+  summarizeFailures,
+} from "./failuresummary.js";
+
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+
+test("Select for failure events", () => {
+  const events = [
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv`,
+      timing: {
+        startTime: new Date(1 * 1000),
+        durationSeconds: 1,
+      },
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-2.drv`,
+      timing: {
+        startTime: new Date(2 * 1000),
+        durationSeconds: 2,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv`,
+      timing: {
+        startTime: new Date(3 * 1000),
+        durationSeconds: 3,
+      },
+    },
+  ];
+
+  expect(getBuildFailures(events)).toStrictEqual([
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv`,
+      timing: {
+        startTime: new Date(1 * 1000),
+        durationSeconds: 1,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv`,
+      timing: {
+        startTime: new Date(3 * 1000),
+        durationSeconds: 3,
+      },
+    },
+  ]);
+});
+
+test("Summarize Failures", async () => {
+  const events = [
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv`,
+      timing: {
+        startTime: new Date(1 * 1000),
+        durationSeconds: 1,
+      },
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-2.drv`,
+      timing: {
+        startTime: new Date(2 * 1000),
+        durationSeconds: 2,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv`,
+      timing: {
+        startTime: new Date(3 * 1000),
+        durationSeconds: 3,
+      },
+    },
+  ];
+
+  const logMaker = async (drv: string): Promise<string | undefined> => {
+    if (drv.includes("dep-1")) {
+      return `${drv}\n`.repeat(9).trimEnd();
+    } else {
+      return `${drv}\n`.repeat(25).trimEnd();
+    }
+  };
+
+  const summary: FailureSummary = (await summarizeFailures(events, logMaker))!;
+
+  expect(summary.markdownLines.join("\n"))
+    .toStrictEqual(`### Build error review :boom:
+> [!NOTE]
+> 2 builds failed
+<details><summary>Failure log: <code>/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-<strong>dep-1</strong>.drv</code></summary>
+
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+
+</details>
+
+<details><summary>Failure log: <code>/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-<strong>dep-3</strong>.drv</code></summary>
+
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+
+</details>
+`);
+
+  expect(summary.logLines.join("\n"))
+    .toStrictEqual(`\u001b[38;2;255;0;0mBuild logs from 2 failures
+The following build logs are also available in the Markdown summary:
+::group::Failed build: /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+::endgroup::
+::group::Failed build: /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+::endgroup::`);
+});
+
+test("Omit some logs if there are too many", async () => {
+  const events = [
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv`,
+      timing: {
+        startTime: new Date(1 * 1000),
+        durationSeconds: 1,
+      },
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-2.drv`,
+      timing: {
+        startTime: new Date(2 * 1000),
+        durationSeconds: 2,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv`,
+      timing: {
+        startTime: new Date(3 * 1000),
+        durationSeconds: 3,
+      },
+    },
+  ];
+
+  const logMaker = async (drv: string): Promise<string | undefined> => {
+    return `${drv}\n`.repeat(5).trimEnd();
+  };
+
+  const summary: FailureSummary = (await summarizeFailures(
+    events,
+    logMaker,
+    500,
+  ))!;
+
+  expect(summary.markdownLines.join("\n"))
+    .toStrictEqual(`### Build error review :boom:
+> [!NOTE]
+> 2 builds failed
+<details><summary>Failure log: <code>/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-<strong>dep-1</strong>.drv</code></summary>
+
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+
+</details>
+
+> [!NOTE]
+> The following failure has been ommitted due to GitHub Actions summary length limitations.
+> The full logs are available in the post-run phase of the Nix Installer Action.
+> * \`/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv\``);
+
+  expect(summary.logLines.join("\n"))
+    .toStrictEqual(`\u001b[38;2;255;0;0mBuild logs from 2 failures
+The following build logs are also available in the Markdown summary:
+::group::Failed build: /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv
+::endgroup::
+The following build logs are NOT available in the Markdown summary:
+::group::Failed build: /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+    /nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-3.drv
+::endgroup::`);
+});

src/failuresummary.ts

@@ -0,0 +1,123 @@
+import { getExecOutput } from "@actions/exec";
+import { DEvent } from "./events.js";
+import { stripVTControlCharacters } from "node:util";
+
+// CI summaries have a max length of "1024k" which I assume to be 1048576 bytes.
+// Generously, the mermaid doc is about 50,000 bytes.
+// Rounding it all down a bit further for wiggle room, that leaves lots of log space.
+const defaultMaxSummaryLength = 995_000;
+
+export function getBuildFailures(events: DEvent[]): DEvent[] {
+  return events.filter((event: DEvent): Boolean => {
+    return event.c === "BuildFailureResponseEventV1";
+  });
+}
+
+export interface FailureSummary {
+  logLines: string[];
+  markdownLines: string[];
+}
+
+export async function summarizeFailures(
+  events: DEvent[],
+  getLog: (drv: string) => Promise<string | undefined> = getLogFromNix,
+  maxLength: number = defaultMaxSummaryLength,
+): Promise<FailureSummary | undefined> {
+  const failures = getBuildFailures(events);
+
+  if (failures.length === 0) {
+    return undefined;
+  }
+
+  const logLines = [];
+  const markdownLines = [];
+
+  logLines.push(
+    `\u001b[38;2;255;0;0mBuild logs from ${failures.length} failure${failures.length === 1 ? "" : "s"}`,
+  );
+  logLines.push(
+    `The following build logs are also available in the Markdown summary:`,
+  );
+  markdownLines.push(`### Build error review :boom:`);
+  markdownLines.push("> [!NOTE]");
+  markdownLines.push(
+    `> ${failures.length} build${failures.length === 1 ? "" : "s"} failed`,
+  );
+
+  const markdownLogChunks: {
+    drv: string;
+    txtLines: string[];
+    mdLines: string[];
+  }[] = [];
+  for (const event of failures) {
+    const markdownLogChunk = [];
+    const txtLogChunk = [];
+    txtLogChunk.push(`::group::Failed build: ${event.drv}`);
+
+    const log =
+      (await getLog(event.drv)) ??
+      "(failure reading the log for this derivation.)";
+    const indented = log.split("\n").map((line) => `    ${line}`);
+
+    markdownLogChunk.push(
+      `<details><summary>Failure log: <code>${event.drv.replace(/^(\/nix[^-]*-)(.*)(\.drv)$/, "$1<strong>$2</strong>$3")}</code></summary>`,
+    );
+    markdownLogChunk.push("");
+
+    for (const line of indented) {
+      txtLogChunk.push(line);
+      markdownLogChunk.push(stripVTControlCharacters(line));
+    }
+    markdownLogChunk.push("");
+    markdownLogChunk.push("</details>");
+    markdownLogChunk.push("");
+
+    markdownLogChunks.push({
+      drv: event.drv,
+      mdLines: markdownLogChunk,
+      txtLines: txtLogChunk,
+    });
+    txtLogChunk.push(`::endgroup::`);
+  }
+
+  const skippedChunks = [];
+
+  // Add markdown log chunks until we exceed the max length
+  let markdownLength = markdownLines.join("\n").length;
+  for (const chunk of markdownLogChunks) {
+    const chunkLength = chunk.mdLines.join("\n").length;
+    if (markdownLength + chunkLength > maxLength) {
+      skippedChunks.push(chunk);
+    } else {
+      logLines.push(...chunk.txtLines);
+      markdownLines.push(...chunk.mdLines);
+      markdownLength += chunkLength;
+    }
+  }
+
+  if (skippedChunks.length > 0) {
+    markdownLines.push(
+      "> [!NOTE]",
+      `> The following ${skippedChunks.length === 1 ? "failure has" : "failures have"} been ommitted due to GitHub Actions summary length limitations.`,
+      "> The full logs are available in the post-run phase of the Nix Installer Action.",
+    );
+
+    logLines.push(
+      "The following build logs are NOT available in the Markdown summary:",
+    );
+    for (const chunk of skippedChunks) {
+      markdownLines.push(`> * \`${chunk.drv}\``);
+      logLines.push(...chunk.txtLines);
+    }
+  }
+
+  return { logLines, markdownLines };
+}
+
+async function getLogFromNix(drv: string): Promise<string | undefined> {
+  const output = await getExecOutput("nix", ["log", drv], {
+    silent: true,
+  });
+
+  return output.stdout;
+}

src/fixHashes.ts

@@ -0,0 +1,38 @@
+import { getExecOutput } from "@actions/exec";
+
+export interface Mismatch {
+  readonly derivation: string;
+  readonly replacement: string;
+}
+
+export interface Fix {
+  readonly line: number;
+  readonly found: string;
+  readonly mismatches: readonly Mismatch[];
+}
+
+export interface FileFix {
+  readonly file: string;
+  readonly fixes: readonly Fix[];
+}
+
+export interface FixHashesOutputV1 {
+  readonly version: "v1";
+  readonly files: readonly FileFix[];
+}
+
+export async function getFixHashes(since: string): Promise<FixHashesOutputV1> {
+  const output = await getExecOutput(
+    "determinate-nixd",
+    ["fix", "hashes", "--json", "--since", since],
+    { silent: true },
+  );
+
+  if (output.exitCode !== 0) {
+    throw new Error(
+      `determinate-nixd fix hashes returned non-zero exit code ${output.exitCode} with the following error output:\n${output.stderr}`,
+    );
+  }
+
+  return JSON.parse(output.stdout);
+}

src/index.ts

@@ -1,7 +1,7 @@
 import * as actionsCore from "@actions/core";
-import * as github from "@actions/github";
 import * as actionsExec from "@actions/exec";
-import { access, writeFile, readFile } from "node:fs/promises";
+import * as github from "@actions/github";
+import { access, readFile, stat } from "node:fs/promises";
 import { join } from "node:path";
 import fs from "node:fs";
 import { userInfo } from "node:os";
@@ -10,6 +10,12 @@ import * as path from "path";
 import { DetSysAction, inputs, platform, stringifyError } from "detsys-ts";
 import { randomUUID } from "node:crypto";
 import got from "got";
+import { setTimeout } from "node:timers/promises";
+import { getFixHashes } from "./fixHashes.js";
+import { annotateMismatches } from "./annotate.js";
+import { getRecentEvents } from "./events.js";
+import { makeMermaidReport } from "./mermaid.js";
+import { summarizeFailures } from "./failuresummary.js";
 
 // Nix installation events
 const EVENT_INSTALL_NIX_FAILURE = "install_nix_failure";
@@ -26,34 +32,39 @@ const EVENT_START_DOCKER_SHIM = "start_docker_shim";
 const EVENT_LOGIN_TO_FLAKEHUB = "login_to_flakehub";
 
 // Other events
-const EVENT_CONCLUDE_WORKFLOW = "conclude_workflow";
+const EVENT_CONCLUDE_JOB = "conclude_job";
+const EVENT_FOD_ANNOTATE = "fod_annotate";
+
+// Feature flag names
+const FEAT_ANNOTATIONS = "hash-mismatch-annotations";
 
 // Facts
+const FACT_DETERMINATE_NIX = "determinate_nix";
 const FACT_HAS_DOCKER = "has_docker";
 const FACT_HAS_SYSTEMD = "has_systemd";
 const FACT_IN_ACT = "in_act";
 const FACT_IN_NAMESPACE_SO = "in_namespace_so";
 const FACT_NIX_INSTALLER_PLANNER = "nix_installer_planner";
 
-type WorkflowConclusion =
-  | "success"
-  | "failure"
-  | "cancelled"
-  | "unavailable"
-  | "no-jobs";
+// Flags
+const FLAG_DETERMINATE = "--determinate";
+
+// Pre/post state keys
+const STATE_START_DATETIME = "DETERMINATE_NIXD_START_DATETIME";
 
 class NixInstallerAction extends DetSysAction {
+  determinate: boolean;
   platform: string;
   nixPackageUrl: string | null;
   backtrace: string | null;
   extraArgs: string | null;
   extraConf: string[] | null;
-  flakehub: boolean;
   kvm: boolean;
   githubServerUrl: string | null;
   githubToken: string | null;
   forceDockerShim: boolean;
   init: string | null;
+  jobConclusion: string | null;
   localRoot: string | null;
   logDirectives: string | null;
   logger: string | null;
@@ -84,17 +95,19 @@ class NixInstallerAction extends DetSysAction {
       diagnosticsSuffix: "diagnostic",
     });
 
+    this.determinate =
+      inputs.getBool("determinate") || inputs.getBool("flakehub");
     this.platform = platform.getNixPlatform(platform.getArchOs());
     this.nixPackageUrl = inputs.getStringOrNull("nix-package-url");
     this.backtrace = inputs.getStringOrNull("backtrace");
     this.extraArgs = inputs.getStringOrNull("extra-args");
     this.extraConf = inputs.getMultilineStringOrNull("extra-conf");
-    this.flakehub = inputs.getBool("flakehub");
     this.kvm = inputs.getBool("kvm");
     this.forceDockerShim = inputs.getBool("force-docker-shim");
     this.githubToken = inputs.getStringOrNull("github-token");
     this.githubServerUrl = inputs.getStringOrNull("github-server-url");
     this.init = inputs.getStringOrNull("init");
+    this.jobConclusion = inputs.getStringOrNull("job-status");
     this.localRoot = inputs.getStringOrNull("local-root");
     this.logDirectives = inputs.getStringOrNull("log-directives");
     this.logger = inputs.getStringOrNull("logger");
@@ -121,9 +134,18 @@ class NixInstallerAction extends DetSysAction {
     await this.scienceDebugFly();
     await this.detectAndForceDockerShim();
     await this.install();
+    actionsCore.saveState(STATE_START_DATETIME, new Date().toISOString());
   }
 
   async post(): Promise<void> {
+    await this.annotateMismatches();
+    try {
+      await this.summarizeExecution();
+    } catch (err: unknown) {
+      this.recordEvent("summarize-execution:error", {
+        exception: stringifyError(err),
+      });
+    }
     await this.cleanupDockerShim();
     await this.reportOverall();
   }
@@ -519,15 +541,6 @@ class NixInstallerAction extends DetSysAction {
       }
       extraConf += "\n";
     }
-    if (this.flakehub) {
-      try {
-        const flakeHubNetrcFile = await this.flakehubLogin();
-        extraConf += `netrc-file = ${flakeHubNetrcFile}`;
-        extraConf += "\n";
-      } catch (e) {
-        actionsCore.warning(`Failed to set up FlakeHub: ${e}`);
-      }
-    }
     if (this.extraConf !== null && this.extraConf.length !== 0) {
       extraConf += this.extraConf.join("\n");
       extraConf += "\n";
@@ -553,13 +566,9 @@ class NixInstallerAction extends DetSysAction {
     return executionEnv;
   }
 
-  private async executeInstall(binaryPath: string): Promise<number> {
-    const executionEnv = await this.executionEnvironment();
-    actionsCore.debug(
-      `Execution environment: ${JSON.stringify(executionEnv, null, 4)}`,
-    );
-
+  private get installerArgs(): string[] {
     const args = ["install"];
+
     if (this.planner) {
       this.addFact(FACT_NIX_INSTALLER_PLANNER, this.planner);
       args.push(this.planner);
@@ -570,11 +579,36 @@ class NixInstallerAction extends DetSysAction {
 
     if (this.extraArgs) {
       const extraArgs = stringArgv(this.extraArgs);
-      args.concat(extraArgs);
+      args.push(...extraArgs);
     }
 
+    if (this.determinate) {
+      this.addFact(FACT_DETERMINATE_NIX, true);
+
+      actionsCore.info(
+        `Installing Determinate Nix using the ${FLAG_DETERMINATE} flag`,
+      );
+
+      if (!this.extraArgs) {
+        args.push(FLAG_DETERMINATE);
+      }
+
+      if (this.extraArgs && !this.extraArgs.includes(FLAG_DETERMINATE)) {
+        args.push(FLAG_DETERMINATE);
+      }
+    }
+
+    return args;
+  }
+
+  private async executeInstall(binaryPath: string): Promise<number> {
+    const executionEnv = await this.executionEnvironment();
+    actionsCore.debug(
+      `Execution environment: ${JSON.stringify(executionEnv, null, 4)}`,
+    );
+
     this.recordEvent(EVENT_INSTALL_NIX_START);
-    const exitCode = await actionsExec.exec(binaryPath, args, {
+    const exitCode = await actionsExec.exec(binaryPath, this.installerArgs, {
       env: {
         ...executionEnv,
         ...process.env, // To get $PATH, etc
@@ -603,8 +637,13 @@ class NixInstallerAction extends DetSysAction {
         );
         await this.executeUninstall();
       } else {
-        // We're already installed, and not reinstalling, just set GITHUB_PATH and finish early
+        // We're already installed, and not reinstalling, just log in to FlakeHub, set GITHUB_PATH and finish early
         await this.setGithubPath();
+
+        if (this.determinate) {
+          await this.flakehubLogin();
+        }
+
         actionsCore.info("Nix was already installed, using existing install");
         return;
       }
@@ -623,7 +662,6 @@ class NixInstallerAction extends DetSysAction {
       }
     }
 
-    // Normal just doing of the install
     actionsCore.startGroup("Installing Nix");
     const binaryPath = await this.fetchBinary();
     await this.executeInstall(binaryPath);
@@ -632,7 +670,12 @@ class NixInstallerAction extends DetSysAction {
     if (this.forceDockerShim) {
       await this.spawnDockerShim();
     }
+
     await this.setGithubPath();
+
+    if (this.determinate) {
+      await this.flakehubLogin();
+    }
   }
 
   async spawnDockerShim(): Promise<void> {
@@ -714,6 +757,10 @@ class NixInstallerAction extends DetSysAction {
           dir: "/tmp",
           readOnly: false,
         },
+        {
+          dir: "/usr",
+          readOnly: true,
+        },
         {
           dir: "/nix",
           readOnly: false,
@@ -737,6 +784,14 @@ class NixInstallerAction extends DetSysAction {
         }
       }
 
+      const plausibleDeterminateOptions = [];
+      const plausibleDeterminateArguments = [];
+      if (this.determinate) {
+        plausibleDeterminateOptions.push("--entrypoint");
+        plausibleDeterminateOptions.push("/usr/local/bin/determinate-nixd");
+        plausibleDeterminateArguments.push("daemon");
+      }
+
       this.recordEvent(EVENT_START_DOCKER_SHIM);
       const exitCode = await actionsExec.exec(
         "docker",
@@ -754,8 +809,10 @@ class NixInstallerAction extends DetSysAction {
           "--name",
           `determinate-nix-shim-${this.getUniqueId()}-${randomUUID()}`,
         ]
+          .concat(plausibleDeterminateOptions)
           .concat(mountArguments)
-          .concat(["determinate-nix-shim:latest"]),
+          .concat(["determinate-nix-shim:latest"])
+          .concat(plausibleDeterminateArguments),
         {
           silent: true,
           listeners: {
@@ -785,10 +842,92 @@ class NixInstallerAction extends DetSysAction {
       }
     }
 
+    const maxDurationSeconds = 120;
+    const delayPerAttemptInMiliseconds = 50;
+    const maxAttempts =
+      (maxDurationSeconds * 1000) / delayPerAttemptInMiliseconds;
+    let didSucceed = false;
+
+    for (let attempt = 0; attempt <= maxAttempts; attempt += 1) {
+      if (await this.doesTheSocketExistYet()) {
+        didSucceed = true;
+        break;
+      }
+
+      await setTimeout(50);
+    }
+
+    if (!didSucceed) {
+      throw new Error("Timed out waiting for the Nix Daemon");
+    }
+
     actionsCore.endGroup();
 
     return;
   }
+
+  async doesTheSocketExistYet(): Promise<boolean> {
+    const socketPath = "/nix/var/nix/daemon-socket/socket";
+    try {
+      await stat(socketPath);
+      return true;
+    } catch (error: unknown) {
+      // eslint-disable-next-line no-undef
+      if ((error as NodeJS.ErrnoException).code === "ENOENT") {
+        actionsCore.debug(`Socket '${socketPath}' does not exist yet`);
+        return false;
+      }
+
+      actionsCore.warning(
+        `Error waiting for the Nix Daemon socket: ${stringifyError(error)}`,
+      );
+      this.recordEvent("docker-shim:wait-for-socket", {
+        exception: stringifyError(error),
+      });
+      throw error;
+    }
+  }
+
+  async summarizeExecution(): Promise<void> {
+    const startDate = new Date(actionsCore.getState(STATE_START_DATETIME));
+    const events = await getRecentEvents(startDate);
+
+    const mermaidSummary = makeMermaidReport(events);
+    const failureSummary = await summarizeFailures(events);
+
+    if (mermaidSummary || failureSummary) {
+      actionsCore.summary.addRaw(
+        `## ![](https://avatars.githubusercontent.com/u/80991770?s=30) Determinate Nix build summary`,
+        true,
+      );
+      actionsCore.summary.addRaw("\n", true);
+    }
+
+    if (mermaidSummary !== undefined) {
+      actionsCore.summary.addRaw(mermaidSummary, true);
+      actionsCore.summary.addRaw("\n", true);
+    }
+
+    if (failureSummary !== undefined) {
+      for (const logLine of failureSummary.logLines) {
+        actionsCore.info(logLine);
+      }
+
+      actionsCore.summary.addRaw(failureSummary.markdownLines.join("\n"), true);
+      actionsCore.summary.addRaw("\n", true);
+    }
+
+    if (mermaidSummary || failureSummary) {
+      actionsCore.summary.addRaw("---", true);
+      actionsCore.summary.addRaw(
+        `_Please let us know what you think about this summary on the [Determinate Systems Discord](https://determinate.systems/discord)._`,
+        true,
+      );
+      actionsCore.summary.addRaw("\n", true);
+      await actionsCore.summary.write();
+    }
+  }
+
   async cleanupDockerShim(): Promise<void> {
     const containerId = actionsCore.getState("docker_shim_container_id");
 
@@ -830,13 +969,19 @@ class NixInstallerAction extends DetSysAction {
   async setGithubPath(): Promise<void> {
     // Interim versions of the `nix-installer` crate may have already manipulated `$GITHUB_PATH`, as root even! Accessing that will be an error.
     try {
-      const nixVarNixProfilePath = "/nix/var/nix/profiles/default/bin";
-      const homeNixProfilePath = `${process.env["HOME"]}/.nix-profile/bin`;
-      actionsCore.addPath(nixVarNixProfilePath);
-      actionsCore.addPath(homeNixProfilePath);
-      actionsCore.info(
-        `Added \`${nixVarNixProfilePath}\` and \`${homeNixProfilePath}\` to \`$GITHUB_PATH\``,
-      );
+      const paths = [];
+
+      if (this.determinate) {
+        paths.push("/usr/local/bin");
+      }
+
+      paths.push("/nix/var/nix/profiles/default/bin");
+      paths.push(`${process.env["HOME"]}/.nix-profile/bin`);
+
+      for (const p of paths) {
+        actionsCore.addPath(p);
+        actionsCore.debug(`Added \`${p}\` to \`$GITHUB_PATH\``);
+      }
     } catch {
       actionsCore.info(
         "Skipping setting $GITHUB_PATH in action, the `nix-installer` crate seems to have done this already. From `nix-installer` version 0.11.0 and up, this step is done in the action. Prior to 0.11.0, this was only done in the `nix-installer` binary.",
@@ -844,31 +989,43 @@ class NixInstallerAction extends DetSysAction {
     }
   }
 
-  async flakehubLogin(): Promise<string> {
-    this.recordEvent(EVENT_LOGIN_TO_FLAKEHUB);
-    const netrcPath = `${process.env["RUNNER_TEMP"]}/determinate-nix-installer-netrc`;
+  async flakehubLogin(): Promise<void> {
+    const canLogin =
+      process.env["ACTIONS_ID_TOKEN_REQUEST_URL"] &&
+      process.env["ACTIONS_ID_TOKEN_REQUEST_TOKEN"];
 
-    const jwt = await actionsCore.getIDToken("api.flakehub.com");
+    if (!canLogin) {
+      const pr = github.context.payload.pull_request;
+      const base = pr?.base?.repo?.full_name;
+      const head = pr?.head?.repo?.full_name;
 
-    await writeFile(
-      netrcPath,
-      [
-        `machine api.flakehub.com login flakehub password ${jwt}`,
-        `machine flakehub.com login flakehub password ${jwt}`,
-      ].join("\n"),
-    );
+      if (pr && base !== head) {
+        actionsCore.info(
+          `Not logging in to FlakeHub: GitHub Actions does not allow OIDC authentication from forked repositories ("${head}" is not the same repository as "${base}").`,
+        );
+        return;
+      }
 
-    actionsCore.info("Logging in to FlakeHub.");
-
-    // the join followed by a match on ^... looks silly, but extra_config
-    // could contain multi-line values
-    if (this.extraConf?.join("\n").match(/^netrc-file/m)) {
-      actionsCore.warning(
-        "Logging in to FlakeHub conflicts with the Nix option `netrc-file`.",
+      actionsCore.info(
+        `Not logging in to FlakeHub: GitHub Actions has not provided OIDC token endpoints; please make sure that \`id-token: write\` and \`contents: read\` are set for this step's (or job's) permissions.`,
       );
+      actionsCore.info(
+        `For more information, see https://docs.determinate.systems/guides/github-actions/#nix-installer-action`,
+      );
+      return;
     }
 
-    return netrcPath;
+    actionsCore.startGroup("Logging in to FlakeHub");
+    this.recordEvent(EVENT_LOGIN_TO_FLAKEHUB);
+    try {
+      await actionsExec.exec(`determinate-nixd`, ["login", "github-action"]);
+    } catch (e: unknown) {
+      actionsCore.warning(`FlakeHub Login failure: ${stringifyError(e)}`);
+      this.recordEvent("flakehub-login:failure", {
+        exception: stringifyError(e),
+      });
+    }
+    actionsCore.endGroup();
   }
 
   async executeUninstall(): Promise<number> {
@@ -896,9 +1053,36 @@ class NixInstallerAction extends DetSysAction {
     try {
       await access(receiptPath);
       // There is a /nix/receipt.json
+      actionsCore.info(
+        "\u001b[32m Nix is already installed: found /nix/receipt.json \u001b[33m",
+      );
       return true;
     } catch {
       // No /nix/receipt.json
+    }
+
+    try {
+      const exitCode = await actionsExec.exec("nix", ["--version"], {});
+
+      if (exitCode === 0) {
+        actionsCore.info(
+          "\u001b[32m Nix is already installed: `nix --version` exited 0 \u001b[33m",
+        );
+        // Working existing installation of `nix` available, possibly a self-hosted runner
+        return true;
+      }
+    } catch {
+      // nix --version was not successful
+    }
+
+    return false;
+  }
+
+  private async canAccessKvm(): Promise<boolean> {
+    try {
+      await access("/dev/kvm", fs.constants.R_OK | fs.constants.W_OK);
+      return true;
+    } catch {
       return false;
     }
   }
@@ -909,6 +1093,12 @@ class NixInstallerAction extends DetSysAction {
     const isRoot = currentUser.uid === 0;
     const maybeSudo = isRoot ? "" : "sudo";
 
+    // First check to see whether the current user can open the KVM device node
+    if (await this.canAccessKvm()) {
+      return true;
+    }
+
+    // The current user can't access KVM, so try adding a udev rule to allow access to all users and groups
     const kvmRules = "/etc/udev/rules.d/99-determinate-nix-installer-kvm.rules";
     try {
       const writeFileExitCode = await actionsExec.exec(
@@ -1010,63 +1200,14 @@ class NixInstallerAction extends DetSysAction {
 
   async reportOverall(): Promise<void> {
     try {
-      this.recordEvent(EVENT_CONCLUDE_WORKFLOW, {
-        conclusion: await this.getWorkflowConclusion(),
+      this.recordEvent(EVENT_CONCLUDE_JOB, {
+        conclusion: this.jobConclusion ?? "unknown",
       });
     } catch (e) {
       actionsCore.debug(`Error submitting post-run diagnostics report: ${e}`);
     }
   }
 
-  private async getWorkflowConclusion(): Promise<
-    undefined | WorkflowConclusion
-  > {
-    if (this.githubToken == null) {
-      return undefined;
-    }
-
-    try {
-      const octokit = github.getOctokit(this.githubToken);
-      const jobs = await octokit.paginate(
-        octokit.rest.actions.listJobsForWorkflowRun,
-        {
-          owner: github.context.repo.owner,
-          repo: github.context.repo.repo,
-          /* eslint-disable camelcase */
-          run_id: github.context.runId,
-        },
-      );
-
-      actionsCore.debug(`awaited jobs: ${jobs}`);
-      const job = jobs
-        .filter((candidate) => candidate.name === github.context.job)
-        .at(0);
-      if (job === undefined) {
-        return "no-jobs";
-      }
-
-      const outcomes = (job.steps ?? []).map((j) => j.conclusion ?? "unknown");
-
-      // Possible values: success, failure, cancelled, or skipped
-      // from: https://docs.github.com/en/actions/learn-github-actions/contexts
-
-      if (outcomes.includes("failure")) {
-        // Any failures fails the job
-        return "failure";
-      }
-      if (outcomes.includes("cancelled")) {
-        // Any cancellations cancels the job
-        return "cancelled";
-      }
-
-      // Assume success if no jobs failed or were canceled
-      return "success";
-    } catch (e) {
-      actionsCore.debug(`Error determining final disposition: ${e}`);
-      return "unavailable";
-    }
-  }
-
   private get defaultPlanner(): string {
     if (this.isMacOS) {
       return "macos";
@@ -1078,6 +1219,40 @@ class NixInstallerAction extends DetSysAction {
       );
     }
   }
+
+  private async annotateMismatches(): Promise<void> {
+    if (!this.determinate) {
+      return;
+    }
+
+    const active = this.getFeature(FEAT_ANNOTATIONS)?.variant;
+    if (!active) {
+      actionsCore.debug("The annotations feature is disabled for this run");
+      return;
+    }
+
+    try {
+      actionsCore.debug("Getting hash fixes from determinate-nixd");
+
+      const since = actionsCore.getState(STATE_START_DATETIME);
+      const mismatches = await getFixHashes(since);
+      if (mismatches.version !== "v1") {
+        throw new Error(
+          `Unsupported \`determinate-nixd fix hashes\` output (got ${mismatches.version}, expected v1)`,
+        );
+      }
+
+      actionsCore.debug("Annotating mismatches");
+      const count = annotateMismatches(mismatches);
+      this.recordEvent(EVENT_FOD_ANNOTATE, { count });
+    } catch (error) {
+      // Don't hard fail the action if something exploded; this feature is only a nice-to-have
+      actionsCore.warning(`Could not consume hash mismatch events: ${error}`);
+      this.recordEvent("annotation-mismatch-execution:error", {
+        exception: stringifyError(error),
+      });
+    }
+  }
 }
 
 type ExecuteEnvironment = {

src/mermaid.test.ts

@@ -0,0 +1,171 @@
+import { mermaidify, makeMermaidReport } from "./mermaid.js";
+import { DEvent, parseEvents } from "./events.js";
+import { expect, test } from "vitest";
+
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+
+function generateEvents(count: number): DEvent[] {
+  const events: DEvent[] = [];
+
+  for (let i = 0; i < count; i++) {
+    events.push({
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: `/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-${i}.drv`,
+      timing: {
+        startTime: new Date(i * 1000),
+        durationSeconds: i,
+      },
+    });
+  }
+
+  return events;
+}
+
+test("Create a very large report doc and make sure it is small enough", () => {
+  {
+    const report = makeMermaidReport(generateEvents(2000))!;
+
+    // Assert the `.drv` suffix was pruned (1 reference = the NOTE at the end)
+    expect(report.match(/\.drv/g)!.length).equals(1);
+
+    // Assert the `/nix/store` prefix was pruned (1 reference = the NOTE at the end)
+    expect(report.match(/\/nix\/store\//g)!.length).equals(1);
+
+    // Assert that some events were pruned
+    expect(report.match(/dep-/g)!.length).lessThan(2000);
+    expect(report.match(/dep-/g)!.length).greaterThan(1500);
+
+    expect(report).toContain("suffix, and builds that took less than 3");
+
+    expect(report.length).lessThan(50200);
+    expect(report.length).greaterThan(49000);
+  }
+});
+
+test("Create a medium large report doc and make sure it is small enough", () => {
+  {
+    const eventCount = 675;
+    const report = makeMermaidReport(generateEvents(eventCount))!;
+
+    // Assert the `.drv` suffix was pruned (1 reference = the NOTE at the end)
+    expect(report.match(/\.drv/g)!.length).equals(1);
+
+    // Assert the `/nix/store` prefix was pruned (1 reference = the NOTE at the end)
+    expect(report.match(/\/nix\/store\//g)!.length).equals(1);
+
+    // Assert that no lines were pruned
+    expect(report.match(/dep-/g)!.length).toStrictEqual(eventCount);
+
+    expect(report).toContain(
+      "suffixes have been removed to make the graph small enough to render",
+    );
+
+    expect(report.length).lessThan(50200);
+    expect(report.length).greaterThan(18000);
+  }
+});
+
+test("Create a small report doc and make sure it isn't pruned", () => {
+  {
+    const report = makeMermaidReport(generateEvents(100))!;
+
+    // Assert 100 events have the `.drv` suffix, ie: were not pruned
+    expect(report.match(/\.drv/g)!.length).equals(100);
+
+    // Assert 100 events have the `.drv` suffix, ie: were not pruned
+    expect(report.match(/\/nix\/store\//g)!.length).equals(100);
+
+    expect(report.length).lessThan(50000);
+  }
+});
+
+test("Generate a really big report and shrink it", () => {
+  const events = generateEvents(1000);
+
+  const originalLength = mermaidify(events, -1)!.length;
+  const limitedLengthZero = mermaidify(events, 0)!.length;
+  const limitedLengthOne = mermaidify(events, 1)!.length;
+  const limitedLengthTwo = mermaidify(events, 2)!.length;
+
+  expect(originalLength).greaterThan(limitedLengthZero);
+  expect(limitedLengthZero).greaterThan(limitedLengthOne);
+  expect(limitedLengthOne).greaterThan(limitedLengthTwo);
+});
+
+test("Generate a rough report of various length", () => {
+  const events = parseEvents([
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-0.drv",
+      outputs: ["/nix/store/qwlgz5da3pfb53gqpgdmazaj9jczrnly-dep-0"],
+      timing: {
+        startTime: "2025-04-11T14:38:02Z",
+        stopTime: "2025-04-11T14:38:05Z",
+        durationSeconds: 0,
+      },
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv",
+      outputs: ["/nix/store/qwlgz5da3pfb53gqpgdmazaj9jczrnly-dep-1"],
+      timing: {
+        startTime: "2025-04-11T14:38:02Z",
+        stopTime: "2025-04-11T14:38:05Z",
+        durationSeconds: 1,
+      },
+    },
+    {
+      v: "1",
+      c: "BuiltPathResponseEventV1",
+      drv: "/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-2.drv",
+      outputs: ["/nix/store/qwlgz5da3pfb53gqpgdmazaj9jczrnly-dep-2"],
+      timing: {
+        startTime: "2025-04-11T14:38:02Z",
+        stopTime: "2025-04-11T14:38:05Z",
+        durationSeconds: 2,
+      },
+    },
+    {
+      v: "1",
+      c: "BuildFailureResponseEventV1",
+      drv: "/nix/store/ykvbksjqrza2zpj6nkbycrdfwgfdpr8g-hash-mismatch-md5-base16.drv",
+      timing: {
+        startTime: "2025-04-11T14:38:05Z",
+        stopTime: "2025-04-11T14:38:09Z",
+        durationSeconds: 4,
+      },
+    },
+  ]);
+
+  expect(mermaidify(events, -1)).toStrictEqual(`\`\`\`mermaid
+gantt
+    dateFormat X
+    axisFormat %Mm%Ss
+/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-0.drv (0s):d, 0, 0s
+/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-1.drv (1s):d, 0, 1s
+/nix/store/rz9hrpay90sjrid5hx3x8v606ji679xa-dep-2.drv (2s):d, 0, 2s
+/nix/store/ykvbksjqrza2zpj6nkbycrdfwgfdpr8g-hash-mismatch-md5-base16.drv (4s):crit, 3, 4s
+\`\`\``);
+
+  expect(mermaidify(events, 0)).toStrictEqual(`\`\`\`mermaid
+gantt
+    dateFormat X
+    axisFormat %Mm%Ss
+dep-0 (0s):d, 0, 0s
+dep-1 (1s):d, 0, 1s
+dep-2 (2s):d, 0, 2s
+hash-mismatch-md5-base16 (4s):crit, 3, 4s
+\`\`\``);
+
+  expect(mermaidify(events, 1)).toStrictEqual(`\`\`\`mermaid
+gantt
+    dateFormat X
+    axisFormat %Mm%Ss
+dep-1 (1s):d, 0, 1s
+dep-2 (2s):d, 0, 2s
+hash-mismatch-md5-base16 (4s):crit, 3, 4s
+\`\`\``);
+});

src/mermaid.ts

@@ -0,0 +1,90 @@
+import { DEvent } from "./events.js";
+import { truncateDerivation } from "./util.js";
+
+export function makeMermaidReport(events: DEvent[]): string | undefined {
+  // # 50k is the max: https://github.com/mermaid-js/mermaid/blob/c269dc822c528e1afbde34e18a1cad03d972d4fe/src/defaultConfig.js#L55
+  const maxLength = 49900;
+  let mermaid = "";
+  let pruneLevel = -2;
+
+  do {
+    pruneLevel += 1;
+    mermaid = mermaidify(events, pruneLevel) ?? "";
+  } while (mermaid.length > maxLength);
+
+  if (mermaid === undefined) {
+    return undefined;
+  }
+
+  const lines = [
+    "<details open><summary><strong>Build timeline</strong> :hourglass_flowing_sand:</summary>",
+    "", // load bearing whitespace, deleting it breaks the details expander / markdown
+    mermaid,
+    "", // load bearing whitespace, deleting it breaks the details expander / markdown
+  ];
+
+  if (pruneLevel === 0) {
+    lines.push("> [!NOTE]");
+    lines.push(
+      "> `/nix/store/[hash]` and the `.drv` suffixes have been removed to make the graph small enough to render.",
+    );
+  } else if (pruneLevel > 0) {
+    lines.push("> [!NOTE]");
+    lines.push(
+      `> \`/nix/store/[hash]\`, the \`.drv\` suffix, and builds that took less than ${pruneLevel}s have been removed to make the graph small enough to render.`,
+    );
+  }
+
+  lines.push(""); // load bearing whitespace, deleting it breaks the details expander / markdown
+  lines.push("</details>");
+
+  return lines.join("\n");
+}
+
+export function mermaidify(
+  allEvents: DEvent[],
+  pruneLevel: number,
+): string | undefined {
+  const events = allEvents
+    .filter(
+      (event) =>
+        event.c === "BuiltPathResponseEventV1" ||
+        event.c === "BuildFailureResponseEventV1",
+    )
+    .sort(
+      (a, b) => a.timing.startTime.getTime() - b.timing.startTime.getTime(),
+    );
+
+  const firstEvent = events.at(0);
+  if (firstEvent === undefined) {
+    return undefined;
+  }
+
+  const zeroMoment = firstEvent.timing.startTime.getTime();
+
+  const lines = [
+    "```mermaid",
+    "gantt",
+    "    dateFormat X",
+    "    axisFormat %Mm%Ss",
+  ];
+
+  for (const event of events) {
+    const duration = event.timing.durationSeconds;
+    if (duration < pruneLevel) {
+      continue;
+    }
+
+    const label = pruneLevel >= 0 ? truncateDerivation(event.drv) : event.drv;
+    const tag = event.c === "BuildFailureResponseEventV1" ? "crit" : "d";
+    const relativeStartTime =
+      (event.timing.startTime.getTime() - zeroMoment) / 1000;
+
+    lines.push(
+      `${label} (${duration}s):${tag}, ${relativeStartTime}, ${duration}s`,
+    );
+  }
+  lines.push("```");
+
+  return lines.join("\n");
+}

src/util.ts

@@ -0,0 +1,3 @@
+export function truncateDerivation(drv: string): string {
+  return drv.replace(/^\/nix\/store\/[a-z0-9]+-/, "").replace(/\.drv$/, "");
+}

tsconfig.json

@@ -1,6 +1,6 @@
 {
   "compilerOptions": {
-    "target": "ES2020" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
+    "target": "ES2022" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
     "module": "Node16",
     "moduleResolution": "NodeNext",
     "outDir": "./dist",
@@ -11,5 +11,5 @@
     "resolveJsonModule": true,
     "declaration": true
   },
-  "exclude": ["node_modules", "**/*.test.ts", "dist"]
+  "exclude": ["node_modules", "dist"]
 }