On Tue, Nov 1, 2022 at 4:53 PM Ævar Arnfjörð Bjarmason [off-list ref] wrote:

I believe you might be trying to re-invent "make -B" :)

True, in the simple case, but if you
  git diff HEAD --name-only --diff-filter=AM | xargs touch
that should consolidate the modified times on disk of the files of that commit

It needs a bit more work, something like
  pre_checkout=$(git rev-parse HEAD)
  git checkout XYX &&
  git diff pre_checkout...XYZ --name-only --diff-filter=AM | xargs touch
but something like that can work around the inconsistent ordered
modified times after a checkout