Removing build folder from git

Well you may just do the following,

• Remove the line from gitignore for now.
• Locally delete the folder.
• Push out the change so the folder gets deleted from remote as well.
• Now add the line to gitignore.

I recently faced the problem and that is what i did.

remove those build files (or whole folder) from your computer

rm -r [direction to files]

then add, commit and push all your changes (actually the change will be removing those files from repository), if you have set .gitignore file properly, git will stop tracking those files