Troubleshooting Chrome and Chromium Flag Configuration on Pop!_OS

Pop!_OS, a popular Linux distribution favored by STEM and creative professionals, offers a robust and customizable environment. However, even seasoned Linux users can occasionally encounter unexpected issues. This article dives into a specific problem reported by a Pop!_OS user: Chrome and Chromium failing to recognize custom flag configurations.

The Issue: Chrome/Chromium Ignoring Configuration Files

A user on the r/pop_os subreddit sought help with a peculiar problem. After migrating from Mint, a friend was trying to configure Chrome and Chromium with a specific flag (--disable-features=ExtensionsToolbarMenu). The standard method of creating chrome-flags.conf and chromium-flags.conf files in the ~/.config/ directory wasn't working.

Despite verifying file ownership, permissions, and syntax, neither browser seemed to acknowledge the configuration files. Even directly modifying the .desktop files proved ineffective.

Understanding Chrome/Chromium Flag Configuration

Before diving into potential solutions, it's crucial to understand how Chrome and Chromium typically handle custom flags.

• Configuration Files: The preferred method involves creating chrome-flags.conf and chromium-flags.conf files in the ~/.config/ directory. Each line in these files represents a flag to be applied when the respective browser launches.
• .desktop Files: Modifying the .desktop files located in /usr/share/applications/ (system-wide) or ~/.local/share/applications/ (user-specific) is another approach. This involves adding the flag to the Exec= line.
• Command Line: Flags can also be passed directly when launching the browser from the command line.

When troubleshooting, it's useful to confirm the expected behaviour by testing the flags in other linux distributions such as Arch Linux.

Potential Solutions and Troubleshooting Steps

Based on the original post and common Linux troubleshooting practices, here's a breakdown of potential solutions:

1. Double-Check File Paths and Names:

   • Case Sensitivity: Linux is case-sensitive. Ensure the filenames are exactly chrome-flags.conf and chromium-flags.conf.
   • Hidden Files: Confirm the .config directory isn't accidentally hidden.
   • Correct Directory: Verify the files are located in ~/.config/, which expands to /home/[username]/.config/.

2. Verify File Content and Syntax:

   • Single Flag per Line: Each flag should be on its own line in the configuration file.
   • Correct Flag Syntax: Double-check the flag's syntax. Typos are common culprits. For example, confirm that --disable-features=ExtensionsToolbarMenu is correctly written.

3. Permissions and Ownership:

   • User Ownership: The user running Chrome/Chromium must own the configuration files. Use ls -l ~/.config/chrome-flags.conf to verify. The output should show the correct username.
   • Read Permissions: The user needs read permissions on the files. Permissions should be at least 644 (rw-r--r--).

4. Check for Conflicting Configurations:

   • Command-Line Flags: If the browser is launched with command-line flags, they might override the configuration file settings.
   • Browser Extensions: Certain browser extensions might interfere with flag settings. Try disabling extensions temporarily to see if that resolves the issue.

5. Browser Updates and Compatibility:

   • Recent Updates: Sometimes, browser updates can introduce unexpected changes. Check if the issue arose immediately after an update.
   • Flag Deprecation: The flag itself might be deprecated or no longer function as expected in the current browser version. Consult the Chrome/Chromium documentation for flag status.

6. Debugging with strace:

   • The original poster used strace to identify whether Chrome was attempting to access the configuration file. This is a powerful debugging technique. If strace shows that Chrome/Chromium isn't even trying to open the configuration file, it suggests a deeper issue.

7. SELinux/AppArmor:

   • While less common on Pop!_OS than other distributions, Security-Enhanced Linux (SELinux) or AppArmor might be interfering with Chrome's ability to access the configuration files. Check the system logs for any SELinux/AppArmor denials related to Chrome or the configuration files. If denials are present, you may need to adjust the security policies.

8. Profile Corruption:

   • In rare cases, a corrupted browser profile can cause unexpected behavior. Try creating a new browser profile and see if the flags work correctly in the new profile.

9. Pop!_OS Specific Issues:

   • Systemd Services: If Chrome/Chromium is launched via a systemd service, the service file might be overriding the configuration settings.
   • Environment Variables: Check for any environment variables that might be affecting Chrome/Chromium's behavior.

Example: Using strace for Debugging

The strace command is invaluable for debugging. Here's an example of how to use it:

strace -f google-chrome --flag-to-test 2>&1 | grep chrome-flags.conf

Replace google-chrome with the actual executable name and --flag-to-test with the flag you're trying to configure. The output should show whether Chrome is attempting to access the chrome-flags.conf file.

Moving Forward

Troubleshooting configuration issues can be frustrating, but by systematically checking each potential cause, you can often pinpoint the root of the problem. The key is to be methodical, verify each step, and use debugging tools like strace to gain deeper insights into the browser's behavior. If the problem persists, consider seeking further assistance from the Pop!_OS community or the Chrome/Chromium support channels.