Try to find out where things are failing.

.github/workflows/ci.yaml

@@ -51,6 +51,7 @@ jobs:
       - name: Retouch
         run: |
           cd $GITHUB_WORKSPACE
+          ls
           git ls-tree -r --name-only HEAD | while read filename; do
             unixtime=$(git log -1 --format="%at" -- "${filename}")
             touchtime=$(date -d @$unixtime +'%Y%m%d%H%M.%S')