fix: open repos when ~/.gitconfig has conflict markers

[hewigovens]

Summary

jj-lib opens the colocated Git repo with gix strict_config(true) and the default (non-isolated) config sources. If ~/.gitconfig is a symlink into a repo (the hewigovens/dotfiles install.sh pattern: ~/.gitconfig → ~/dotfiles/.gitconfig) and that file has conflict markers, jj itself refuses to load the repo:

Internal error: The repository appears broken or inaccessible
Caused by:
1: Failed to open git repository
2: Failed to load the git configuration
3: Got an unexpected token on line 3 ... '<<<<<<< Co'

JayJay then showed “Failed to open repository” until the conflict was resolved by hand — which is the chicken-and-egg: you need the repo open to resolve .gitconfig.

Workspace::load only displays Cannot read the repo; the gix parse error is on the source chain. Matching that Display string is how the first revision missed the retry.

Change

When a path contains .jj and Workspace::load fails, retry with GIT_CONFIG_GLOBAL pointed at an empty file. That lets JayJay open the repo so the conflicted .gitconfig can be resolved in the UI.

If the retry also fails, the error keeps the full cause chain and adds a hint about conflict markers / a symlinked ~/.gitconfig. A .jj directory that fails to load is reported as an internal error instead of “repository not found.”

This is a workaround, not an upstream jj fix. The CLI still fails in the same situation.

Test plan

• Regression: Repo::open + refresh_working_copy succeed when GIT_CONFIG_GLOBAL contains jj conflict markers (child process so parallel fixtures are not poisoned)
• cargo test -p jayjay-core --test repo
• cargo test -p jayjay-core --lib --test working_copy --test conflicts --test workspace_presence

[chatgpt-codex-connector]

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-31T03:04:14.274917Z	6cf4b77	Draft marked ready

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Reviewed commit: 6cf4b771f9

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