Debug Like a Pro with 'git bisect'

Most programmers spent hours checking git commits to identify which commit introduced the bug. It’s frustrating. But instead of manually checking commit after commit, Git has a built-in tool that saves your time using Binary Search — git bisect! Let me walk you through it. It’s easier than you think. Step 1: Start Bisecting First, tell Git you want to start looking for the bad commit: git bisect start That’s it! Now Git knows you’re about to go on a debugging hunt. Step 2: Mark a "Good" and "Bad" Commit Now, we need to give Git some context. Find a past commit where everything worked fine and mark it as good: git bisect good Then, mark the commit where the bug appeared as bad: git bisect bad Don’t know the exact good commit? No worries—just pick an older one where you think things were stable. Step 3: Let Git Do the Heavy Lifting Now comes the magic! Git will check out a commit in the middle of the range. You test it and tell Git whether the bug is there or not. If the bug isn’t there, run: git bisect good If the bug exists, run: git bisect bad Git keeps narrowing it down until it finds the exact commit that introduced the issue. Step 4: End Bisect & Fix the Bug Once Git pinpoints the problematic commit, reset everything back to normal: git bisect reset Then, take a look at the commit, figure out what went wrong, and fix the bug at its source! BTW if you have a test script that can detect the bug automatically, you don’t even have to manually test each commit! Just run: git bisect run ./test-script.sh Git will keep running the script until it finds the bad commit — completely hands-free debugging! If you haven’t tried git bisect yet, give it a shot! It might just become your new favorite debugging tool. Don't forget to share this. Might help someone in your network.

Mar 9, 2025 - 11:42

Most programmers spent hours checking git commits to identify which commit introduced the bug. It’s frustrating. But instead of manually checking commit after commit, Git has a built-in tool that saves your time using Binary Search — git bisect!

Let me walk you through it. It’s easier than you think.

Step 1: Start Bisecting

First, tell Git you want to start looking for the bad commit:
git bisect start

That’s it! Now Git knows you’re about to go on a debugging hunt.

Step 2: Mark a "Good" and "Bad" Commit

Now, we need to give Git some context. Find a past commit where everything worked fine and mark it as good:
git bisect good

Then, mark the commit where the bug appeared as bad:
git bisect bad

Don’t know the exact good commit? No worries—just pick an older one where you think things were stable.

Step 3: Let Git Do the Heavy Lifting

Now comes the magic! Git will check out a commit in the middle of the range. You test it and tell Git whether the bug is there or not.

If the bug isn’t there, run:
git bisect good

If the bug exists, run:
git bisect bad

Git keeps narrowing it down until it finds the exact commit that introduced the issue.

Step 4: End Bisect & Fix the Bug

Once Git pinpoints the problematic commit, reset everything back to normal:
git bisect reset

Then, take a look at the commit, figure out what went wrong, and fix the bug at its source!

BTW if you have a test script that can detect the bug automatically, you don’t even have to manually test each commit! Just run:
git bisect run ./test-script.sh

Git will keep running the script until it finds the bad commit — completely hands-free debugging!

If you haven’t tried git bisect yet, give it a shot! It might just become your new favorite debugging tool.

Don't forget to share this. Might help someone in your network.