GIT: Error search with git bisect

47.1. Using git bisect

git bisect The git bisect command allows you to run a binary search through the commit history to identify the commit which introduced an issue. You specify a range of commits and a script that the bisect command uses to identify whether a commit is good or bad.

This script must return 0 if the condition is fulfilled and non-zero if the condition is not fulfilled.

47.2. git bisect example

Create a new Git repository, create the text1.txt file and commit it to the repository. Do a few more changes, remove the file and again do a few more changes.

We use a simple shell script which checks the existence of a file. Ensure that this file is executable.

#!/bin/bash
FILE=$1

if [ -f $FILE ];
then
   exit 0;
else
   exit 1;
fi

Afterwards use the git bisect command to find the bad commit. First you use the git bisect start command to define a commit known to be bad (showing the problem) and a commit known to be good (not showing the problem).

# define that bisect should check
# the last 5 commits
git bisect start HEAD HEAD~5

Afterwards run the bisect command using the shell script.

# assumes that the check script
# is a directory above the current
git bisect run ../check.sh test1.txt

The above commands serve as an example. The existence of a file can be easier  verified with the git bisect command: git bisect run test -f test1.txt