GoGitActionCache failed to open bare git %s with ref %s at %

Error message

GoGitActionCache failed to open bare git %s with ref %s at %s: %w

What it means

GoGitActionCache.Fetch (pkg/runner/action_cache.go) maintains bare git repos under c.Path named safeFilename(cacheDir)+".git". It first tries git.PlainInit(gitPath, true) to create a bare repo; if the repo already exists it opens it with git.PlainOpen. This error wraps failure of BOTH calls: PlainInit failed with something other than ErrRepositoryAlreadyExists (permissions, disk full, invalid path) or PlainOpen failed on an existing but corrupt directory.

Source

Thrown at pkg/runner/action_cache.go:47

type GoGitActionCache struct {
	Path string
}

func (c GoGitActionCache) Fetch(ctx context.Context, cacheDir, url, ref, token string) (string, error) {
	logger := common.Logger(ctx)

	gitPath := path.Join(c.Path, safeFilename(cacheDir)+".git")

	logger.Infof("GoGitActionCache fetch %s with ref %s at %s", url, ref, gitPath)

	gogitrepo, err := git.PlainInit(gitPath, true)
	if errors.Is(err, git.ErrRepositoryAlreadyExists) {
		logger.Debugf("GoGitActionCache cache hit %s with ref %s at %s", url, ref, gitPath)
		gogitrepo, err = git.PlainOpen(gitPath)
	}
	if err != nil {
		return "", fmt.Errorf("GoGitActionCache failed to open bare git %s with ref %s at %s: %w", url, ref, gitPath, err)
	}
	tmpBranch := make([]byte, 12)
	if _, err := rand.Read(tmpBranch); err != nil {
		return "", fmt.Errorf("GoGitActionCache failed to generate random tmp branch %s with ref %s at %s: %w", url, ref, gitPath, err)
	}
	branchName := hex.EncodeToString(tmpBranch)

	var auth transport.AuthMethod
	if token != "" {
		auth = &http.BasicAuth{
			Username: "token",
			Password: token,
		}
	}
	remote, err := gogitrepo.CreateRemoteAnonymous(&config.RemoteConfig{
		Name: "anonymous",
		URLs: []string{
			url,

View on GitHub (pinned to 4f41128141)

Solutions

Delete the specific corrupt cache repo printed in the error path (the '<...>.git' directory), or the whole cache: rm -rf ~/.cache/act.
Fix permissions: chown -R $(id -u):$(id -g) ~/.cache/act && chmod -R u+rwX ~/.cache/act.
Point act at a writable cache: act --action-cache-path /path/to/writable/dir.
Check disk space (df -h) and filesystem permissions on the parent of the cache path.

Example fix

# before
act  # error: GoGitActionCache failed to open bare git ... : repository does not exist / permission denied

# after
rm -rf ~/.cache/act
act --action-cache-path "$HOME/.cache/act"

Defensive patterns

Strategy: validation

Validate before calling

CACHE="${ACT_CACHE_PATH:-$HOME/.cache/act}"
[ -w "$CACHE" ] || { echo "cache dir not writable: $CACHE"; exit 1; }
# detect corrupt bare repos: a valid one has HEAD and objects/
for d in "$CACHE"/*.git; do [ -f "$d/HEAD" ] || { echo "corrupt: $d"; exit 1; }; done

Prevention

Use a dedicated writable --action-cache-path per environment/user.
Clean ~/.cache/act after interrupted runs.
Ensure consistent ownership of the cache directory across act invocations.

When it happens

Trigger: The host cache directory (~/.cache/act by default, or --action-cache-path) has wrong ownership/permissions, is on a read-only filesystem, is full, or contains a corrupt/partially-created *.git directory from a previously interrupted run.

Common situations: Running act as a different user than the one that created ~/.cache/act; a killed act process left a half-initialized bare repo; Docker desktop VM file mapping issues; SELinux/AppArmor denial on the cache path.

Related errors

AI-assisted analysis of nektos/act@4f41128141 (2026-08-15). Data as JSON: /api/errors/fb7551a03fee6a96. Report an issue: GitHub.