git.day/8 • See all at git.day

Usually Git can handle moving files around in the repo, keeping track of renames and moves. However Git doesn't actually follow moves around; as discussed in Git of the day #7: git add --intent-to-add, commits are not diffs from the previous commit, but rather snapshots of state. Sometimes Git needs a bit of a hand setting the index to produce the index for the new state.

The most common case where Git needs a hand is after renaming a file changing its case. Let's rename a file changing its case only¹ and see what happens:

$ ls
Foo
$ mv Foo foo
$ ls
foo
$ git status
On branch master
nothing to commit, working tree clean

This is the problem: the filesystem has changed but Git has not picked up the move. This can be resolved with git mv in place of the regular mv.

$ git mv Foo foo
$ git status
On branch master
changes to be committed:
  renamed:   Foo -> foo

While Git is great at tracking changes to the filesystem, this extra command helps with edge cases such as this, ensuring changes can be added correctly.

1. This example is on macOS with an APFS volume. ↩︎