$ git clone -n https://src.fedoraproject.org/rpms/rust-directories.git /var/lib/mock/f39-build-1445104-32648/root/chroot_tmpdir/scmroot/rust-directories
Cloning into '/var/lib/mock/f39-build-1445104-32648/root/chroot_tmpdir/scmroot/rust-directories'...
$ git fetch origin 2e332708b48b7332e91ff3e553a0c4b15df38245:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-directories
 * [new ref]         2e332708b48b7332e91ff3e553a0c4b15df38245 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e33270 Update to version 5.0.1; Fixes RHBZ#2179559