magic-merge-commit

Magic Merge Commit

Resolves conflicts where a pull request's base branch was squash-merged into main. After the squash-merge, Git no longer connects the branch to its history, so merging main produces spurious conflicts. This skill runs a tool that creates a merge commit with two parents (main + branch tip), wiring the histories back together so main merges cleanly.

When to use

All of the following are true:

• The user is on a branch that was based on another PR's branch.
• That other PR was squash-merged into main.
• Merging main into the current branch now conflicts.

Prerequisites (verify before running)

1. jbang is on PATH. If not, a gg.cmd file in the repository root works as a fallback (see https://github.com/eirikb/gg#ggcmd).
2. The GITHUB_TOKEN environment variable is set with read access to the repository. The tool authenticates via GitHubBuilder().fromEnvironment().
3. The current Git branch is the one based on the squashed PR — not main.

If a prerequisite is missing, tell the user how to fix it and stop.

Run

Ask the user for <pr-number> — the number of the PR that was squash-merged into main. Then run:

jbang do@koppor/magic-merge-commit <pr-number>

Fallback when jbang is not installed (gg.cmd in repo root):

• Linux/macOS: sh ./gg.cmd jbang do@koppor/magic-merge-commit <pr-number>
• Windows: .\gg.cmd jbang do@koppor/magic-merge-commit <pr-number>

After running

The tool creates a merge commit with main and the branch tip as parents. Confirm with git log --graph --oneline -5 that the magic commit exists, then the user can merge main without conflicts.