$ git clone -n https://src.fedoraproject.org/rpms/rust-tempfile.git /var/lib/mock/f39-build-1645377-40341/root/chroot_tmpdir/scmroot/rust-tempfile
Cloning into '/var/lib/mock/f39-build-1645377-40341/root/chroot_tmpdir/scmroot/rust-tempfile'...
$ git fetch origin f9bd75f628b6e818eb19fadf3ad799cc7a3e91e6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tempfile
 * [new ref]         f9bd75f628b6e818eb19fadf3ad799cc7a3e91e6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f9bd75f Update to version 3.8.0; Fixes RHBZ#2224425