[BUG] Checkpoints commit to wrong repo when GIT_DIR is set (Dev Containers)

[nonsleepr]

Type

Bug

Problem / Value

In Dev Containers that set GIT_DIR, Roo’s checkpoint commits go to that location instead of the shadow repository. This causes unintended commits in the wrong repo and developer confusion.

Context

Affects developers using VS Code Dev Containers that define a global GIT_DIR (e.g., via remoteEnv). Occurs whenever Roo creates a checkpoint (reported on v3.19.7). The expected behavior is that checkpoint operations always target Roo’s shadow repo regardless of ambient git env.

Reproduction

1 Configure a Dev Container with remoteEnv setting GIT_DIR (e.g., GIT_DIR=/somewhere)
2) Start a Roo session and trigger a checkpoint
3) Observe the commit landing in GIT_DIR instead of the shadow repo

Expected

Checkpoint commits are isolated to Roo’s shadow repository and do not honor external GIT_DIR.

Actual

Commits are made to the path specified by GIT_DIR when present.

Acceptance Criteria

• Checkpoint/shadow-repo git operations are isolated from inherited environment variables (GIT_DIR, GIT_WORK_TREE, etc.)
• Behavior consistently targets the shadow repo across Dev Containers and local environments
• Change is scoped so other user workflows that rely on GIT_DIR outside checkpoints are unaffected

Notes

• Ensure checkpoint operations sanitize or override relevant git env for the duration of the operation only

[nonsleepr]

Was hoping #4509 helps, but it's probably a deeper issue.

[daniel-lxs]

This appears to be an environment variable inheritance issue. When GIT_DIR is set in the Dev Container's .remoteEnv, it fundamentally alters how git interprets repository locations.

It seems that when git executes any command, it follows this precedence:

1. First checks GIT_DIR environment variable
2. Falls back to .git in the current directory
3. Searches parent directories for .git

In this case, the shadow repository initialization at https://github.com/RooCodeInc/Roo-Code/blob/main/src/services/checkpoints/ShadowCheckpointService.ts#L77 creates a SimpleGit instance that inherits the parent process environment. Despite correctly configuring core.worktree to point to the workspace directory, the presence of GIT_DIR overrides the local .git directory detection.

The simple-git library doesn't provide built-in environment isolation, so all git operations respect the inherited GIT_DIR, causing commits to be written to the wrong repository. This explains why the logs show successful shadow repo initialization but the actual commits end up in the GIT_DIR location.

A potential solution would involve creating the SimpleGit instance with a sanitized environment that explicitly unsets GIT_DIR, ensuring git operations remain confined to the intended shadow repository.