gohugoio/hugo · error

failed to map git repo for module %s: %v

Error message

failed to map git repo for module %s: %v

What it means

After successfully cloning a module's origin repo into the GitInfo cache, Hugo runs gitmap over that clone at the module's pinned revision (origin.Hash) to build a filename→commit map. This error means that mapping step failed — the clone exists but git log/rev operations against the recorded revision did not succeed.

Source

Thrown at hugolib/gitinfo.go:176

}

func (g *gitInfo) loadModuleRepos(cfg gitInfoConfig) error {
	for _, mod := range cfg.Modules {
		if !isGitModule(mod) {
			continue
		}

		loadGitInfo := sync.OnceValues(func() (*gitmap.GitRepo, error) {
			origin := mod.Origin()

			cloneDir, err := ensureClone(cfg, origin)
			if err != nil {
				return nil, fmt.Errorf("failed to clone %s: %v", origin.URL, err)
			}

			repo, err := mapModuleRepo(cfg, cloneDir, origin.Hash)
			if err != nil {
				return nil, fmt.Errorf("failed to map git repo for module %s: %v", mod.Path(), err)
			}
			return repo, nil
		})

		g.moduleRepoLoaders[mod.Dir()] = loadGitInfo
	}

	return nil
}

// ensureClone ensures a blobless clone of the module's origin repo exists in the cache.
func ensureClone(cfg gitInfoConfig, origin modules.ModuleOrigin) (string, error) {
	key := "repo_" + hashing.XxHashFromStringHexEncoded(origin.URL)
	info, err := cfg.GitInfoCache.GetOrCreateInfo(key, func(id string) error {
		cloneDir := cfg.GitInfoCache.AbsFilenameFromID(id)
		if err := os.MkdirAll(cloneDir, 0o777); err != nil {
			return err
		}

View on GitHub ↗ (pinned to 8a468df065)

Solutions

1. Clear the GitInfo cache (remove the repo_* directories under Hugo's cache dir, or `hugo --gc` / delete cacheDir) so the clone is recreated fresh.
2. Run `hugo mod get -u <module>` to re-resolve the module to a revision that exists upstream.
3. Check the wrapped git error for the specific revision; verify it exists with `git ls-remote <origin>`.
4. If the upstream history was rewritten, pin the module to a valid tag/commit in your module config.

// confirm each module dir is inside a git work tree
out, err := exec.Command("git", "-C", moduleDir, "rev-parse", "--is-inside-work-tree").Output()
if err != nil || strings.TrimSpace(string(out)) != "true" {
    log.Printf("module %s not a git repo; GitInfo unavailable", moduleDir)
}

if err := build(); err != nil && strings.Contains(err.Error(), "failed to map git repo for module") {
    // fall back: build without git info for vendored/non-git modules
    cfg.Set("enableGitInfo", false)
    err = build()
}

When it happens

Trigger: mapModuleRepo failing inside the sync.OnceValues loader in loadModuleRepos: the module's pinned hash (from go.sum/module origin metadata) not present in the blobless clone (e.g. force-pushed or GC'd upstream), a stale/corrupted cached clone, or git command failures when gitmap walks the revision.

Common situations: Module upstream rewrote history so the pinned commit no longer exists; the GitInfo cache holds an old clone that predates new commits and was not fetched; interrupted earlier clone leaving a broken repo in the cache; version-pinned modules whose tags were moved.

Related errors

• failed to clone %s: %v
• failed to load Git data: %w
• failed to load modules: %w
• failed to create config from modules config: %w
• no modules loaded (need at least the main module)

AI-assisted analysis of gohugoio/hugo@8a468df065 (2026-07-31). Data as JSON: /data/errors/fd73932ebf00c5f6.json. Report an issue: GitHub ↗.