ListInstallations: failed to list installed plugins: %s

Error message

ListInstallations: failed to list installed plugins: %s

What it means

Requirement.ListInstallations() wraps any failure from getPluginBinaries() (which globs the plugin directories for installed binaries) with this prefixed message. The underlying error is a filesystem/glob problem, not a plugin problem — Packer could not enumerate what is installed.

Source

Thrown at packer/plugin-getter/plugins.go:228

	return retMatches, err
}

// ListInstallations lists unique installed versions of plugin Requirement pr
// with opts as a filter.
//
// Installations are sorted by version and one binary per version is returned.
// Last binary detected takes precedence: in the order 'FromFolders' option.
//
// At least one opts.Checksumers must be given for a binary to be even
// considered.
func (pr Requirement) ListInstallations(opts ListInstallationsOptions) (InstallList, error) {
	res := InstallList{}
	log.Printf("[TRACE] listing potential installations for %q that match %q. %#v", pr.Identifier, pr.VersionConstraints, opts)

	matches, err := pr.getPluginBinaries(opts)
	if err != nil {
		return nil, fmt.Errorf("ListInstallations: failed to list installed plugins: %s", err)
	}

	for _, path := range matches {
		fname := filepath.Base(path)
		if fname == "." {
			continue
		}

		checksumOk := false
		for _, checksummer := range opts.Checksummers {

			cs, err := checksummer.GetCacheChecksumOfFile(path)
			if err != nil {
				log.Printf("[TRACE] GetChecksumOfFile(%q) failed: %v", path, err)
				continue
			}

			if err := checksummer.ChecksumFile(cs, path); err != nil {

View on GitHub (pinned to eb36e3c3e4)

Solutions

Inspect the wrapped inner error (%s) to identify the failing path, then verify that directory exists and is readable (ls the PACKER_PLUGIN_PATH / ~/.packer.d/plugins tree).
Fix the environment: set PACKER_PLUGIN_PATH or HOME/XDG_CONFIG_HOME to a valid, accessible directory.
Recreate the plugin directory with correct permissions, then retry the packer command.

Defensive patterns

Strategy: try-catch

Validate before calling

for _, dir := range opts.FromFolders {
	if fi, err := os.Stat(dir); err != nil || !fi.IsDir() {
		return fmt.Errorf("plugin dir %q missing or not a directory", dir)
	}
}

Try / catch

installs, err := req.ListInstallations(opts)
if err != nil {
	return fmt.Errorf("%v: check PACKER_PLUGIN_PATH and %s are readable", err, defaultPluginDir)
}

Prevention

Verify PACKER_PLUGIN_PATH/HOME point to accessible directories before running packer
Ensure plugin directories exist with correct permissions in CI images
Log the resolved plugin directory at debug level during setup

When it happens

Trigger: Calling ListInstallations when pr.getPluginBinaries(opts) fails: the plugin directory path is unreadable, a glob pattern is invalid, or an I/O error occurs while walking ~/.packer.d/plugins/... (often because opts.FromFolders or env-configured paths point somewhere inaccessible).

Common situations: PACKER_PLUGIN_PATH points to a nonexistent or permission-restricted directory; home directory redirection (HOME/XDG) wrong in CI containers; a path that is a file rather than a directory.

Related errors

AI-assisted analysis of hashicorp/packer@eb36e3c3e4 (2026-09-05). Data as JSON: /api/errors/5b56abb9848110fd. Report an issue: GitHub.