google-gemini/gemini-cli · error · Error

Cannot install extension "${newExtensionName}" because a dir

Error message

Cannot install extension "${newExtensionName}" because a directory with that name already exists. Please remove it manually.

What it means

Thrown when the computed destination directory (`ExtensionStorage(name).getExtensionDir()`) already exists on disk for a fresh install, or for an update that renames the extension. The manager will not overwrite an existing directory because it cannot safely attribute it.

Source

Thrown at packages/cli/src/config/extension-manager.ts:362

          newExtensionConfig,
          requestConsentOverride ?? this.requestConsent,
          newHasHooks,
          previousExtensionConfig,
          previousHasHooks,
          newSkills,
          previousSkills,
          isMigrating,
        );
        const extensionId = getExtensionId(newExtensionConfig, installMetadata);
        const destinationPath = new ExtensionStorage(
          newExtensionName,
        ).getExtensionDir();

        if (
          (!isUpdate || newExtensionName !== previousName) &&
          fs.existsSync(destinationPath)
        ) {
          throw new Error(
            `Cannot install extension "${newExtensionName}" because a directory with that name already exists. Please remove it manually.`,
          );
        }

        let previousSettings: Record<string, string> | undefined;
        let wasEnabledGlobally = false;
        let wasEnabledWorkspace = false;
        if (isUpdate && previousExtensionConfig) {
          const previousExtensionId = previous?.installMetadata
            ? getExtensionId(previousExtensionConfig, previous.installMetadata)
            : extensionId;
          previousSettings = await getEnvContents(
            previousExtensionConfig,
            previousExtensionId,
            this.workspaceDir,
          );
          if (newExtensionName !== previousName) {
            wasEnabledGlobally = this.extensionEnablementManager.isEnabled(

View on GitHub (pinned to 5024443c72)

Solutions

Remove the destination directory manually and retry the install.
Run `gemini extensions uninstall <name>` to let the manager clean it up.
Check `~/.gemini/extensions/<name>` (and the workspace extensions dir) for stale folders.

Example fix

// before
$ gemini extensions install owner/repo  # dir exists
// after
$ rm -rf ~/.gemini/extensions/my-ext && gemini extensions install owner/repo

Defensive patterns

Strategy: validation

Validate before calling

const dest = new ExtensionStorage(newExtensionName).getExtensionDir();
if ((!isUpdate || newExtensionName !== previousName) && fs.existsSync(dest)) {
  throw new Error(`Destination ${dest} already exists; remove it manually.`);
}

Type guard

function destinationIsClear(dest: string): boolean {
  return !fs.existsSync(dest);
}

Prevention

Run `gemini extensions uninstall` rather than `rm -rf` to keep state consistent.
Before install, check the destination path and clean stale dirs.
Treat leftover directories after a failed install as a defect to clean up.

When it happens

Trigger: A previous install/uninstall cycle left the directory behind; the user manually created a directory with the same name; a prior copy step was interrupted leaving a partial directory.

Common situations: Interrupted installs; partial uninstalls; manual `mkdir`/`cp` into the extensions dir; switching machines where half a directory was synced.

Related errors

AI-assisted analysis of google-gemini/gemini-cli@5024443c72 (2026-08-12). Data as JSON: /api/errors/687184dcd8bbf84e. Report an issue: GitHub.