git branchless init --main-branch <branch> does not set main branch if set in .git/config

[mlcui-corp]

Description of the bug

This is a pretty obscure bug:

Command log

$ git sl
The application panicked (crashed).
Message:  A fatal error occurred: 
   0: Could not find repository main branch

Location:
   git-branchless-lib/src/core/repo_ext.rs:79

Suggestion: 
The main branch "stable" could not be found in your repository
at path: "~/chromiumos/.repo/projects/src/third_party/chromiumos-overlay.git/".
These branches exist: ["ReferenceName(\"refs/heads/main\")"]
Either create it, or update the main branch setting by running:

    git branchless init --main-branch <branch>

Note that remote main branches are no longer supported as of v0.6.0. See
https://github.com/arxanas/git-branchless/discussions/595 for more details.

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.
Location: git-branchless/src/commands/mod.rs:221

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

$ git branchless init --main-branch main
Created config file at ~/chromiumos/.repo/projects/src/third_party/chromiumos-overlay.git/branchless/config
Installing hooks: post-applypatch, post-checkout, post-commit, post-merge, post-rewrite, pre-auto-gc, reference-transaction
Successfully installed git-branchless.
To uninstall, run: git branchless init --uninstall

$ git sl
The application panicked (crashed).
Message:  A fatal error occurred: 
   0: Could not find repository main branch

Location:
   git-branchless-lib/src/core/repo_ext.rs:79

Suggestion: 
The main branch "stable" could not be found in your repository
at path: "~/chromiumos/.repo/projects/src/third_party/chromiumos-overlay.git/".
These branches exist: ["ReferenceName(\"refs/heads/main\")"]
Either create it, or update the main branch setting by running:

    git branchless init --main-branch <branch>

Note that remote main branches are no longer supported as of v0.6.0. See
https://github.com/arxanas/git-branchless/discussions/595 for more details.

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.
Location: git-branchless/src/commands/mod.rs:221

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

$ cat .git/config
# snip...
[include]
        path = branchless/config
# snip...
[branchless "core"]
        mainBranch = stable

If a user set the main branch using git config branchless.core.mainBranch <branch>, then that branch gets deleted, git-branchless suggests running git branchless init --main-branch <branch> to set it... but that updates the branch in .git/branchless/config, which is then overridden by the branch set in .git/config.

Expected behavior

The .git/config entry below should be deleted upon running git branchless init --main-branch main:

[branchless "core"]
        mainBranch = stable

Alternatively, the config entry should be updated with the new main branch name. This might be more reasonable as all other config options set in .git/branchless/config are typically never changed by the user (aliases, excluding refs/branchless/* from log, and removing the detached HEAD advice).

Actual behavior

The .git/config entry wasn't deleted or updated, resulting in the same "missing main branch" error.

Version of rustc

No response

Automated bug report

No response

Version of git-branchless

b66f76c (patched on top of f25babf)

Version of git

git version 2.40.0.634.g4ca3ef3211-goog

[arxanas]

Thanks for reporting. This is similar to #338 and #694. I commented in #338:

The best solution is probably to not install the branchless.core.mainBranch setting to the same config file where we install aliases, and instead indiscriminately install it to .git/config. [...] For this specific issue, we can probably close this issue due to #588, because the recommended way of setting the main branch is now git branchless init --main-branch <main>, which will install the main branch configuration in the right place.

This might just be a documentation issue (it looks like https://github.com/arxanas/git-branchless/wiki/Configuration suggests using git config to configure the main branch, which is "wrong"), but it would probably be best to delete or use the existing .git/config entry.