How do I install the Bisect skill?

Run npx skillmds@latest add ryanb/bisect in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Bisect skill do?

Git bisect to find the first bad commit by running a test command. It is listed under Coding & Dev Tools on SkillMD.

Is Bisect safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Bisect?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Bisect free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Bisect?

ryanb (@ryanb) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Bisect by ryanb — Agent Skill

Name: Bisect
Author: ryanb

File contents

bisect — Find the First Bad Commit

Use git bisect to binary-search through commit history and find the first commit that introduced a failure.

Step 1: Ensure clean working tree

Check that there are no staged or unstaged changes. If there are, stop and tell the user they need a clean working tree before bisecting, since git bisect checks out older commits.

git status --porcelain

If the output is non-empty, stop and ask the user to commit or stash their changes first.

Step 2: Determine the test command

Use $ARGUMENTS to understand what the user wants to test. This should describe a command or check that fails on the current commit. Determine the exact shell command to run.

Step 3: Verify the current commit is bad

Run the test command on the current commit (HEAD). If it passes (exits 0), stop and tell the user — the current commit doesn't exhibit the failure, so there's nothing to bisect.

Step 4: Find a good commit

Start searching backwards from HEAD in steps of 10 commits to find a commit where the test passes.

git stash --include-untracked -q 2>/dev/null; true
git checkout HEAD~10 --quiet

Run the test command. If it still fails, go back another 10 commits (HEAD~10 from the current position). Repeat until either:

A passing commit is found, or
You've gone back 100+ commits without finding a passing one — stop and ask the user for guidance (maybe a known-good commit SHA).

Once a good commit is found, note its SHA.

Step 5: Run git bisect

Return to the original branch first, then start bisecting:

git checkout - --quiet
git bisect start
git bisect bad
git bisect good <good-commit-sha>

Git will check out a middle commit. Run the test command on it:

If the test fails → git bisect bad
If the test passes → git bisect good

Repeat until git reports the first bad commit.

Step 6: Record the result and clean up

Save the first bad commit SHA and message. Then reset:

git bisect reset

Step 7: Report

Tell the user the first bad commit, including:

The commit SHA
The commit message
The commit author and date
A brief git show --stat of the commit so they can see which files changed

---name: bisectdescription: Git bisect to find the first bad commit by running a test command.---# bisect — Find the First Bad CommitUse `git bisect` to binary-search through commit history and find the first commit that introduced a failure.## Step 1: Ensure clean working treeCheck that there are no staged or unstaged changes. If there are, **stop and tell the user** they need a clean working tree before bisecting, since git bisect checks out older commits.```bashgit status --porcelain```If the output is non-empty, stop and ask the user to commit or stash their changes first.## Step 2: Determine the test commandUse `$ARGUMENTS` to understand what the user wants to test. This should describe a command or check that fails on the current commit. Determine the exact shell command to run.## Step 3: Verify the current commit is badRun the test command on the current commit (HEAD). If it **passes** (exits 0), stop and tell the user — the current commit doesn't exhibit the failure, so there's nothing to bisect.## Step 4: Find a good commitStart searching backwards from HEAD in steps of 10 commits to find a commit where the test passes.```bashgit stash --include-untracked -q 2>/dev/null; truegit checkout HEAD~10 --quiet```Run the test command. If it still fails, go back another 10 commits (`HEAD~10` from the current position). Repeat until either:- A passing commit is found, or- You've gone back 100+ commits without finding a passing one — stop and ask the user for guidance (maybe a known-good commit SHA).Once a good commit is found, note its SHA.## Step 5: Run git bisectReturn to the original branch first, then start bisecting:```bashgit checkout - --quietgit bisect startgit bisect badgit bisect good <good-commit-sha>```Git will check out a middle commit. Run the test command on it:- If the test **fails** → `git bisect bad`- If the test **passes** → `git bisect good`Repeat until git reports the first bad commit.## Step 6: Record the result and clean upSave the first bad commit SHA and message. Then reset:```bashgit bisect reset```## Step 7: ReportTell the user the first bad commit, including:- The commit SHA- The commit message- The commit author and date- A brief `git show --stat` of the commit so they can see which files changed

Frequently asked questions

Bisect