Failed to retrieve the git history for file "${file}" with u

Error message

Failed to retrieve the git history for file "${file}" with unexpected output: ${output}

What it means

Thrown by getFileCommitDate() when git log produced non-empty output but the RESULT: prefix regex failed to match it. The function uses a 'RESULT:%ct' (or 'RESULT:%ct,%an' with includeAuthor) format and parses with a regex; a match failure indicates git emitted something unexpected — most likely a GPG signature line, a hook output, or a git version/format quirk that breaks the assumed output shape.

Source

Thrown at packages/docusaurus-utils/src/vcs/gitUtils.ts:190

  // We only parse the output line starting with our "RESULT:" prefix
  // See why https://github.com/facebook/docusaurus/pull/10022
  const regex = includeAuthor
    ? /(?:^|\n)RESULT:(?<timestamp>\d+),(?<author>.+)(?:$|\n)/
    : /(?:^|\n)RESULT:(?<timestamp>\d+)(?:$|\n)/;

  const output = result.stdout.trim();

  if (!output) {
    throw new FileNotTrackedError(
      `Failed to retrieve the git history for file "${file}" because the file is not tracked by git.`,
    );
  }

  const match = output.match(regex);

  if (!match) {
    throw new Error(
      `Failed to retrieve the git history for file "${file}" with unexpected output: ${output}`,
    );
  }

  const timestampInSeconds = Number(match.groups!.timestamp);
  const timestamp = timestampInSeconds * 1_000;
  const date = new Date(timestamp);

  if (includeAuthor) {
    return {date, timestamp, author: match.groups!.author!};
  }
  return {date, timestamp};
}

let showedGitRequirementError = false;
let showedFileNotTrackedError = false;

type GitCommitInfo = {timestamp: number; author: string};

View on GitHub (pinned to 3f483e80e3)

Solutions

Inspect the output echoed in the error message — compare it to the expected 'RESULT:<timestamp>(,<author>)' shape.
If GPG signature lines are present, ensure no global config forces `log.showSignature=true`; the per-call -c flag should override but a faulty gitrc can interfere.
Disable any git pager or hook that could alter log output (unset GIT_PAGER, run with --no-pager for diagnostics).
If the issue persists, reproduce manually with `git -c log.showSignature=false log --format=RESULT:%ct --max-count=1 -- <file>` to see exactly what git emits.

Example fix

# before — global config forces signed log output
git config --global log.showSignature true

# after
git config --global --unset log.showSignature
# or scope the override per-repo after the build

Defensive patterns

Strategy: try-catch

Validate before calling

import { execaSync } from 'execa';
import path from 'path';

function gitLogOutputMatchesExpected(file: string): boolean {
  const r = execaSync('git', ['-c', 'log.showSignature=false', 'log', '--format=RESULT:%ct', '--max-count=1', '--', path.basename(file)], { cwd: path.dirname(file) });
  return /(?:^|\n)RESULT:\d+/.test(r.stdout.trim());
}

if (!gitLogOutputMatchesExpected(file)) {
  throw new Error('git log output shape is unexpected; check for GPG signatures or hooks.');
}

Try / catch

try {
  await getFileCommitDate(file, { age: 'newest' });
} catch (err) {
  if (err instanceof Error && err.message.includes('with unexpected output')) {
    // inspect err message: the raw git output is appended; check for signature lines or hook noise
  }
  throw err;
}

Prevention

Do not force `log.showSignature=true` globally; Docusaurus passes -c log.showSignature=false per call but a faulty gitrc can interfere.
Avoid global git hooks or pagers that mutate log output.
Reproduce the exact git invocation from the error to see what git emits when this fires.

When it happens

Trigger: git log ran with the RESULT: format string but its stdout, after trimming, does not contain a line matching the expected RESULT:<digits>(,<author>) pattern. The code already passes -c log.showSignature=false to suppress GPG signature noise; a mismatch suggests that suppression did not take effect, the git version misbehaves, or a custom log format hook interfered.

Common situations: Commits signed with GPG where showSignature=false did not suppress the signature (older git versions, or a config override). A global git hook (e.g. a pager or formatter) that mutates log output. A git version with a formatting bug. Concurrent git invocations interleaving output (rare thanks to GitCommandQueue).

Related errors

AI-assisted analysis of facebook/docusaurus@3f483e80e3 (2026-08-12). Data as JSON: /api/errors/e2fa46061ec89b91. Report an issue: GitHub.