unable to close window due to delete_task error

[brooksc]

Bug Report: Closing a "Task" Window Fails with git branch -D -- main Error

Summary

When attempting to close a task window for a task that has already been merged/committed to main, the application throws an unhandled error and the window does not close. The error originates from the tool invoking git branch -D -- main, which git refuses to execute because main is the active branch in a linked git worktree.

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Error Message

Error: Error invoking remote method 'delete_task': Error: Command failed:
git branch -D -- main
error: cannot delete branch 'main' used by worktree at '/home/<user>/.git/<project>'

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Steps to Reproduce

1. Open the application and navigate to a task that has already been completed and merged into main.
2. Attempt to close the task's window (e.g., click the close/dismiss button).
3. Observe the error dialog instead of the window closing cleanly.

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Expected Behavior

The task window closes cleanly. If delete_task involves branch cleanup, it should either:

• Skip deleting main (it should never delete a protected branch like main), or
• Detect that the branch is currently checked out in a worktree and handle the error gracefully.

Actual Behavior

The window fails to close. An error is surfaced:

Error: Error invoking remote method 'delete_task': Error: Command failed:
git branch -D -- main
error: cannot delete branch 'main' used by worktree at '/home/<user>/.git/<project>'

The UI is left in a broken state — the window stays open with no recovery path visible to the user.

---

Impact

• Severity: Medium — blocks basic UI flow for completed tasks
• Workaround: None apparent through the UI; requires manual git worktree remove from the terminal
• Effect: Completed tasks cannot be dismissed; window remains open indefinitely, polluting the workspace

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Root Cause Analysis (user-observed)

The repository has a linked git worktree at a path outside the project directory (under ~/.git/<project>), which has main checked out. This was likely created by the application itself in a prior session.

When delete_task runs git branch -D -- main, git rejects it because main is the active branch of that external worktree. The command should never attempt to delete main at all — it is the default/protected branch — and it should additionally check whether any worktree has the target branch checked out before attempting deletion.

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System Configuration

Field	Value
OS	macOS 26.4.1 (Build 25E253)
git version	2.50.1 (Apple Git-155)
Repo location	Google Drive (via macOS filesystem mount)
Sandbox	Disabled

Git Worktree State at Time of Error

<redacted-home>/.git/<project>                          95f120d [main]          ← stale/orphaned worktree
<project-root>/.worktrees/task/implement-task-048-...   ccb3337 [task/implement-task-048-...]
<project-root>/.worktrees/task/the-heckle-history-...   5dcdfb7 [task/the-heckle-history-...]

Git Branches at Time of Error

* main
+ task/implement-task-048-settings-screen-3a2461
+ task/the-heckle-history-currently-adds-entries-to-the-top-of-the-list-instead-21c5ed
  remotes/origin/HEAD -> origin/main
  remotes/origin/main
  remotes/origin/task/create-an-icon-and-whatever-other-c8a487

---

Suggested Fix

1. Never pass main (or any default/protected branch name) to git branch -D — the delete_task flow should only delete the task's feature branch, not main.
2. Before calling git branch -D <branch>, check git worktree list to confirm no worktree has that branch active; if one does, either skip deletion or remove the worktree first.
3. Handle the error gracefully — if branch deletion fails for any reason, catch the error and still allow the UI window to close so the user is not stuck.

[brooksc]

Correction on the root cause - revised bug report below. I can't find a way to edit the description after the issue is submitted...

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Bug Report: Closing a "Task" Window Fails with git branch -D -- main Error

Summary

When attempting to close a task window for a task that has already been merged/committed to main, the application throws an unhandled error and the window does not close. The error originates from the tool invoking git branch -D -- main, which git refuses because main is the active branch of the main working tree.

---

Error Message

Error: Error invoking remote method 'delete_task': Error: Command failed:
git branch -D -- main
error: cannot delete branch 'main' used by worktree at '/home/<user>/.git/<project>'

---

Steps to Reproduce

1. Open the application and navigate to a task that has already been completed and merged into main.
2. Attempt to close the task's window (e.g., click the close/dismiss button).
3. Observe the error dialog instead of the window closing cleanly.

---

Expected Behavior

The task window closes cleanly. The delete_task flow should only delete the task's feature branch — it should never attempt to delete main or any other protected branch.

Actual Behavior

The window fails to close. An error is surfaced:

Error: Error invoking remote method 'delete_task': Error: Command failed:
git branch -D -- main
error: cannot delete branch 'main' used by worktree at '/home/<user>/.git/<project>'

The UI is left in a broken state — the window stays open with no recovery path visible to the user.

---

Impact

• Severity: Medium — blocks basic UI flow for completed tasks
• Workaround: None apparent through the UI; requires manual intervention in the terminal
• Effect: Completed tasks cannot be dismissed; the window remains open indefinitely, polluting the workspace

---

Root Cause Analysis (user-observed)

This repository uses a .git symlink (not a gitfile) to store the git directory outside the cloud-synced project folder, a common pattern for keeping git objects off Google Drive or similar sync services:

<project-root>/.git  →  /home/<user>/.git/<project>   (symlink)

When git worktree list is run in this configuration, it resolves the symlink and reports the git directory path (/home/<user>/.git/<project>) as the main worktree, rather than the actual working directory:

/home/<user>/.git/<project>    95f120d [main]          ← git-dir path, NOT a separate worktree
<project-root>/.worktrees/task/implement-task-048-...  ccb3337 [task/implement-task-048-...]
<project-root>/.worktrees/task/the-heckle-history-...  5dcdfb7 [task/the-heckle-history-...]

The application appears to parse this output and misinterpret the first entry as a linked worktree with main checked out. It then attempts to clean up by running git branch -D -- main, which git correctly rejects — you cannot delete the currently active branch.

The repo is healthy; git worktree prune reports nothing stale. The bug is entirely in how the tool parses git worktree list output when .git is a symlink.

---

System Configuration

Field	Value
OS	macOS 26.4.1 (Build 25E253)
git version	2.50.1 (Apple Git-155)
Repo location	Google Drive (via macOS filesystem mount)
.git type	Symlink to path outside cloud-sync folder
Sandbox	Disabled

Git Worktree State at Time of Error

/home/<user>/.git/<project>                             95f120d [main]          ← misread as linked worktree
<project-root>/.worktrees/task/implement-task-048-...   ccb3337 [task/implement-task-048-...]
<project-root>/.worktrees/task/the-heckle-history-...   5dcdfb7 [task/the-heckle-history-...]

Git Branches at Time of Error

* main
+ task/implement-task-048-settings-screen-3a2461
+ task/the-heckle-history-currently-adds-entries-to-the-top-of-the-list-instead-21c5ed
  remotes/origin/HEAD -> origin/main
  remotes/origin/main
  remotes/origin/task/<redacted>

---

Suggested Fix

1. Never pass main (or any default/protected branch) to git branch -D — delete_task should only delete the task's feature branch, not main under any circumstances.
2. Fix git worktree list parsing to handle the symlink case — when the first entry's path matches the resolved git directory path rather than a real working tree directory, it should be recognized as the main worktree, not a linked one. Alternatively, use git worktree list --porcelain and check the bare / HEAD fields to distinguish main from linked worktrees.
3. Handle the error gracefully — if branch deletion fails for any reason, catch the error and still allow the UI window to close so the user is not left stuck.

[johannesjo]

Thanks for the thorough writeup and for posting the corrected root-cause analysis — the symlinked-.git parsing theory matches what I found in the code (the realpath() filter in listImportableWorktrees doesn't handle this case).

Before I push a fix, one quick question to pin down the exact path: would you be able to share the persisted task entry for the window that wouldn't close? It lives in the app's state file (on macOS: ~/Library/Application Support/parallel-code/state.json, key: tasks → the task with branchName: "main"). Specifically I'd like to see whether externalWorktree is true, false, or absent — that tells me whether this task was imported by the current code or carried over from an older version, which decides where the guard needs to go.

Feel free to redact paths or anything else; I only need the boolean.