How to fix npm ERR! code 128 npm ERR! git clone --mirror git://github.com/user/repo.git failed with code 128 in npm

npmINTERMEDIATEHIGH

Exit code 128 is a fatal Git error that occurs when npm fails to clone a repository during dependency installation. This typically happens when Git encounters permission denial, network failure, or authentication issues.

What this error means

Exit code 128 is a fatal Git error that occurs when npm fails to clone a repository during dependency installation. This typically happens when npm runs "git clone --mirror" to cache a Git-based dependency. The error indicates that Git encountered an unrecoverable problem such as: - Permission denial (SSH key issues) - Network failure (firewall blocking git:// protocol) - Authentication failure (private repos without credentials) - Directory creation issues (permissions) The --mirror flag creates a bare repository clone used internally by npm for caching, and failure indicates the underlying Git operation could not complete.

How to fix "npm ERR! code 128 npm ERR! git clone --mirror git://github.com/user/repo.git failed with code 128"

1Clear npm cache and verify Git is working

First, clear the npm cache which may contain corrupted Git clone attempts:

bash

npm cache clean --force

Then verify Git is installed and working:

bash

git --version
git config --list

If Git isn't in your PATH, install or reinstall Git.

2Check and fix SSH key configuration

If your package.json contains git+ssh dependencies, ensure SSH keys are properly configured:

bash

# List SSH keys
ls -la ~/.ssh/

# If no key exists, generate one
ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519 -N ""

# Display public key to add to GitHub
cat ~/.ssh/id_ed25519.pub

Then add the public key to GitHub Settings > SSH and GPG keys.

Start the SSH agent and add your key:

bash

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

3Test Git access to the repository

Manually verify you can access the repository:

For SSH:

bash

ssh -vvv [email protected]

For HTTPS:

bash

git clone https://github.com/user/repo.git

If this fails, the issue is with your Git/SSH setup, not npm.

4Switch from SSH to HTTPS if SSH is blocked

Corporate firewalls often block SSH port 22. Configure Git to rewrite SSH URLs to HTTPS:

bash

# Convert SSH URLs to HTTPS
git config --global url."https://github.com/".insteadOf git+ssh://[email protected]
git config --global url."https://github.com/".insteadOf [email protected]:
git config --global url."https://".insteadOf git://

Then retry:

bash

npm cache clean --force
npm install

5Use HTTPS with authentication token for private repos

For private repositories, HTTPS with a token is more reliable:

1. Generate a personal access token on GitHub (Settings > Developer settings)
2. Update package.json with HTTPS format:

json

{
  "dependencies": {
    "my-package": "git+https://<TOKEN>:[email protected]/user/repo.git"
  }
}

Or use .npmrc to configure the token globally.

6Delete package-lock.json and regenerate

Sometimes package-lock.json contains stale references:

bash

rm package-lock.json
rm -rf node_modules/
npm cache clean --force
npm install

This forces npm to re-evaluate all dependencies and use the current URL format.

How to fix npm ERR! code 128 npm ERR! git clone --mirror git://github.com/user/repo.git failed with code 128 in npm

What this error means

Typical symptoms

Common causes

How to fix "npm ERR! code 128 npm ERR! git clone --mirror git://github.com/user/repo.git failed with code 128"

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