Thus Spake the Demigod

At Hashrocket, we use RVM to manage our rubies and gemsets on client projects. We typically specify the version of ruby that’s in production in our .rvmrc, like so:

rvm_gemset_create_on_use_flag=1
rvm 1.8.7-p249@vurl

However, sometimes a machine will have a problem with an installation of ruby, and so we’ll use a different version on that machine. Yeah, the correct solution is to fix the damn ruby, but we solved the problem today by flexing some little-used git fu… updating the index to ignore local changes to a file.

So, our `git status` shows us:

# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#   modified:   .rvmrc
#
no changes added to commit (use "git add" and/or "git commit -a")

Now let’s instruct git to assume our .rvmrc is unchanged:

git update-index --assume-unchanged .rvmrc

And now our `git status` looks much better:

# On branch master
nothing to commit (working directory clean)