Git provides a rather efficient mechanism to find bad commits. Instead of making the user try out every single commit to find out the first one that introduced some particular issue into the code, git bisect allows the user to perform a sort of binary search on the entire history of a repository.
By issuing the command git bisect start, the repository enters bisect mode. After this, all you have to do is identify a bad and a good commit:
git bisect bad # marks the current version as bad
git bisect good {hash or tag} # marks the given hash or tag as good, ideally of some earlier commit
Once this is done, Git will then have a range of commits that it needs to explore. At every step, it will checkout a certain commit from this range, and require you to identify it as good or bad. After which the range will be effectively halved, and the whole search will require a lot less number of steps than the actual number of commits involved in the range. Once the first bad commit has been found, or the bisect mode needs to be ended, the following command can be used to exit the mode and reset the bisection state:
