How to conduct a git bisect
Hello and welcome back to my blog! Today we are going to be discussing how to do a git bisect.
What is a git bisect?
A git bisect is nothing but an operation that uses binary search techniques in order to find a commit (among a large set of commits) that potentially introduced a bug in your code.
How to successfully use git bisect
In order to do a git bisect successfully, you will need the following:
- The commit hash / tag as a start point where we know that the bug is present.
- The commit hash / tag where we know that the bug was NOT present.
Follow these steps to start a bisect.
- Issue the following command to start a git bisect on the branch you are on:
git bisect start - Issue the follwing command to specify the bad commit (by default if no commit is specified, the head of the branch is the starting point.):
git bisect bad [optional: commit_hash] - Issue the following command to specify the commit hash or tag where you know that the bug was not present:
git bisect good [tag/commit_hash]
Once this is done, git will checkout a a commit version that you can then test to see if it is buggy or no. If not, type in git bisect good, if it is buggy, type in git bisect bad.
Repeat this process until you have no more revisions to test. Git will print out a description of the first bad commit. The reference refs/bisect/bad will point to the first bad commit.
A great example of this is shown in gits own documentation: https://git-scm.com/docs/git-bisect which is the source for this blog.
Hope you learned something new! ☺️