git apply is making no changes to files

I have to apply a patch to my repo and am running

git apply --directory=$PWD xxxxx.patch

For reasons I won't go into, I cannot use git am in this instance, and I need to use the directory flag.

git tells me:

$> git apply --directory=$PWD xxxxx.patch
code1/xxxxx.patch:337: trailing whitespace.
         < one partial line of code >
warning: 1 line adds whitespace errors.

I have read that the whitespace warning is nothing serious and should not stop git from applying the patch. However, whatever the reason, git is not applying the patch. None of the current files in the repo are changing. Any idea what to do about this?