GitHub Copilot in VS Code on Linux: Known Compatibility Issues

GitHub Copilot may not activate or provide suggestions in Visual Studio Code on Linux distributions such as Ubuntu, Fedora, or Debian. This problem often stems from missing runtime dependencies, incorrect proxy settings, or outdated VS Code extensions. This article explains the root causes of these compatibility failures and provides step-by-step fixes for each scenario.

Why Copilot Fails on Linux

GitHub Copilot runs as a language server that connects to the GitHub API. On Linux, this server requires a modern glibc version, specifically libc6 2.28 or later. Many enterprise Linux distributions or older LTS releases ship with libc6 2.27 or earlier. When the language server cannot load, VS Code shows no error but Copilot never activates.

A second common cause is network restriction. Copilot must send code context to api.github.com. Corporate firewalls or proxies that block outbound HTTPS traffic prevent the extension from authenticating or generating suggestions. VS Code may display a spinning icon in the status bar without completing the connection.

A third cause is a corrupted or incomplete VS Code installation. Flatpak or Snap versions of VS Code sometimes lack the necessary file system permissions to run the Copilot language server binary. Native .deb or .rpm packages avoid this limitation.

Steps to Diagnose and Fix Copilot on Linux

Check glibc Version

1. Open a terminal
   Run the command ldd --version. The first line shows the glibc version. If it is lower than 2.28, Copilot cannot start.
2. Upgrade glibc if possible
   On Ubuntu, run sudo apt update && sudo apt upgrade libc6. On Fedora, run sudo dnf update glibc. If the distribution does not provide a newer glibc, consider upgrading the OS to a newer release like Ubuntu 22.04 or Fedora 38.
3. Verify the upgrade
   Run ldd --version again. Confirm the version is now 2.28 or higher. Restart VS Code after the upgrade.

Configure Proxy Settings

1. Open VS Code settings
   Press Ctrl+Comma to open Settings. Search for proxy.
2. Set HTTP_PROXY and HTTPS_PROXY
   Enter the proxy URL in the fields Http: Proxy and Https: Proxy. For example, http://proxy.company.com:8080. Do not include authentication credentials in the URL.
3. Set environment variables in shell profile
   Add these lines to ~/.bashrc or ~/.zshrc:
   export HTTP_PROXY=http://proxy.company.com:8080
export HTTPS_PROXY=http://proxy.company.com:8080
   Run source ~/.bashrc and restart VS Code.
4. Test connectivity
   In a terminal, run curl -I https://api.github.com. Expect a 200 or 301 response. If you get a timeout or connection refused, the proxy or firewall is blocking the request.

Reinstall VS Code Using Native Package

1. Remove existing VS Code installation
   If you installed via Flatpak, run flatpak uninstall com.visualstudio.code. For Snap, run sudo snap remove code.
2. Download the .deb or .rpm package
   Go to code.visualstudio.com and download the package for your distribution. For Ubuntu or Debian, choose the .deb file.
3. Install the package
   Run sudo dpkg -i ~/Downloads/code_deb for Debian-based systems. For Fedora, run sudo rpm -i ~/Downloads/code-rpm.
4. Install the GitHub Copilot extension
   Open VS Code, go to the Extensions view, search for GitHub Copilot, and click Install. Sign in with your GitHub account when prompted.

If Copilot Still Has Issues After the Main Fix

Copilot Shows “Not Signed In” Despite Successful Login

This occurs when the authentication token is not stored correctly. Open the command palette with Ctrl+Shift+P, type GitHub Copilot: Sign Out, then sign in again. If the problem persists, delete the cached token file: rm -rf ~/.config/Code/CachedData//github-copilot and restart VS Code.

Copilot Only Suggests Single-Line Completions

Multiline suggestions require the Copilot language server to have enough memory. On low-memory Linux systems, the server may time out. Increase the memory limit by adding "github.copilot.advanced": { "memoryMB": 512 } to your VS Code settings.json file. Restart VS Code after making the change.

Copilot Does Not Work with Remote SSH or Containers

When using the Remote-SSH extension, Copilot runs on the remote machine. The remote host must also meet the glibc requirement and have outbound HTTPS access. Install the Copilot extension on the remote host by selecting Extensions > Install Extension in the remote window. If the remote host uses an older glibc, upgrade it or use a container image based on Ubuntu 22.04 or later.

GitHub Copilot in VS Code on Linux vs Windows: Key Differences

Item	Linux	Windows
glibc dependency	Requires libc6 2.28 or newer	No equivalent dependency; Windows 10 or 11 works out of the box
Proxy configuration	Must set HTTP_PROXY and HTTPS_PROXY in shell or VS Code settings	Uses system proxy settings automatically
Package installation	Native .deb or .rpm recommended; Flatpak and Snap may fail	Installer .exe works universally
Remote SSH support	Remote host must meet same glibc and network requirements	Remote host on Windows or Linux works without extra configuration

To summarize, GitHub Copilot on Linux fails primarily due to an outdated glibc library, missing proxy configuration, or a non-native VS Code package. Check your glibc version with ldd --version and upgrade to 2.28 or higher. Set the HTTP_PROXY and HTTPS_PROXY environment variables if you use a corporate proxy. Reinstall VS Code using the official .deb or .rpm package to avoid permission issues. After applying these fixes, Copilot should generate suggestions reliably in your Linux environment.