What causes "Cannot read baseline %s, file does not exist" in sebastianbergmann/phpunit?

Check the exact path passed to --baseline (relative paths resolve from where you invoke phpunit).

sebastianbergmann/phpunit · error · CannotLoadBaselineException

Cannot read baseline %s, file does not exist

Error message

Cannot read baseline %s, file does not exist

What it means

PHPUnit was told to load a baseline (--baseline=... via configureBaseline) and Reader::read() found no regular file at that path (is_file failed). A baseline is the XML file generated by --generate-baseline that lets PHPUnit ignore known deprecations/notices/warnings; the run refuses to proceed without a readable one.

Source

Thrown at src/Runner/Baseline/Reader.php:40

use PHPUnit\Util\Xml\Loader as XmlLoader;
use PHPUnit\Util\Xml\XmlException;

/**
 * @no-named-arguments Parameter names are not covered by the backward compatibility promise for PHPUnit
 *
 * @internal This class is not covered by the backward compatibility promise for PHPUnit
 */
final readonly class Reader
{
    /**
     * @param non-empty-string $baselineFile
     *
     * @throws CannotLoadBaselineException
     */
    public function read(string $baselineFile): Baseline
    {
        if (!is_file($baselineFile)) {
            throw new CannotLoadBaselineException(
                sprintf(
                    'Cannot read baseline %s, file does not exist',
                    $baselineFile,
                ),
            );
        }

        try {
            $document = (new XmlLoader)->loadFile($baselineFile);
        } catch (XmlException $e) {
            throw new CannotLoadBaselineException(
                sprintf(
                    'Cannot read baseline %s: %s',
                    $baselineFile,
                    trim($e->getMessage()),
                ),
            );
        }

View on GitHub (pinned to f123cdb2a2)

Solutions

Check the exact path passed to --baseline (relative paths resolve from where you invoke phpunit).
Generate the file first: vendor/bin/phpunit --generate-baseline=.phpunit/baseline.xml.
If it should already exist, verify it is committed and present in the CI image.

Example fix

# before
vendor/bin/phpunit --baseline=.phpunit/baseline.xml  # file missing

# after
vendor/bin/phpunit --generate-baseline=.phpunit/baseline.xml
vendor/bin/phpunit --baseline=.phpunit/baseline.xml

Defensive patterns

Strategy: validation

Validate before calling

// Before running with --baseline
if (!is_file($baselinePath)) {
    fwrite(STDERR, "Baseline {$baselinePath} missing; generating it first\n");
    exit(1); // or shell_exec('vendor/bin/phpunit --generate-baseline=' . escapeshellarg($baselinePath));
}

Try / catch

try {
    $baseline = (new Reader())->read($baselineFile);
} catch (CannotLoadBaselineException $e) {
    // regenerate and retry once, or fail with a clear message
}

Prevention

Generate the baseline in the same CI step that consumes it.
Commit the baseline file if teams share it, and verify its path in CI.
Use paths relative to the project root and invoke phpunit from a fixed cwd.

When it happens

Trigger: vendor/bin/phpunit --baseline=.phpunit/baseline.xml when the file was never generated, lives at another path, or the relative path resolves against a different working directory.

Common situations: First run on a new checkout before generating the baseline; path typos; the baseline file not committed to the repo; CI running from a different cwd so the relative path misses.

Related errors

AI-assisted analysis of sebastianbergmann/phpunit@f123cdb2a2 (2026-08-23). Data as JSON: /api/errors/ba3b070de49f05ef. Report an issue: GitHub.