git status
# 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:   readme.txt
#       modified:   requirements.txt
#
no changes added to commit (use "git add" and/or "git commit -a")

I didn't make any changes on those files. But I'm getting this message even if I try:

git checkout -- readme.txt
git checkout -- requirements.txt

When I run:

git diff

it shows the whole file as updated. But the contents are the same.

I tried to delete them and checkout again, but it didn't work.