How .gitignore Works
25 Mar 2014Earlier today I ran into a Git issue within a RubyMotion project. I added a directory to the project’s .gitignore file, but Git seemed to ignore my ignore. Expressed more clearly, Git continued to track a directory that I explicitly told it to ignore.
What?
Either there was a bug in Git, or my understanding of .gitignore was incomplete. It was time for me to dig in and learn more about .gitignore.
What I Learned About .gitignore
The root cause of my problem: Once Git has begun tracking a file or directory, adding it to .gitignore changes nothing. Git will continue to track the file unless we explicitly tell Git to stop tracking the file.
$ git rm --cached [filename]
$
Or, if you want to stop tracking an entire directory (like me in this case)…
$ git rm -r --cached [directoryname]
$
The -r flag will tell Git to stop tracking all of the sub-directories and files within directoryname, recursively.
Git was behaving exactly as designed.
Penalty
I should have known this a long time ago. My penalty: A public admission :-)