@copilot please concentrate on reproducing and describing the race condition in ./script/test-clr. I can't reproduce your results but it's happened several times in a copilot session (reported here clojure/clr.core.cli#4).
I conjecture that the race condition is here in ensure-git-dir (https://github.com/clojure/clr.core.cli/blob/9a09d7e73a15ecefec15c697eb1aff7d54392082/src/dotnet/Cljr/clojure/tools/gitlibs/impl.cljr):
(defn git-clone-bare
[url ^DirectoryInfo git-dir] ;;; ^File
(printerrln "Cloning:" url)
(let [git-path (.FullName git-dir) ;;; .getCanonicalPath
{:keys [exit err] :as ret} (run-git "clone" "--quiet" "--mirror" url git-path)]