fix: set git safe.directory at system level for non-root container users

[brendan-kellam]

Summary

Switches the safe.directory "*" git config in the Dockerfile from --global to --system.

--global writes only to the home directory of the build-time user (/root/.gitconfig). The image intentionally sets no USER directive (see the comment near the entrypoint) and can be run as sourcebot or an arbitrary --user at runtime. In those cases git reads that user's $HOME/.gitconfig, never sees safe.directory, and the "dubious ownership" error this line is meant to prevent still fires.

--system writes to /etc/gitconfig, which is read by every user regardless of who invokes git, so the fix now actually covers all three run modes (root, sourcebot, arbitrary --user).

Risk

Low / net risk reduction:

• RUN runs as root at build time, so it can write /etc/gitconfig.
• /etc/gitconfig is created with default umask (644), world-readable, and nothing later chmods /etc, so non-root runtime users can read it.
• safe.directory is multi-valued and accumulated across config levels, so the lower-precedence system scope can't be clobbered by a user-level gitconfig.

🤖 Generated with Claude Code

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: ed4cc637-9d2f-4f63-870a-aa72ce39b58e

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch brendan/fix-git-system-safe-directory

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}