$ git clone -n https://src.fedoraproject.org/rpms/rust-thiserror.git /var/lib/mock/f40-build-2144759-50871/root/chroot_tmpdir/scmroot/rust-thiserror
Cloning into '/var/lib/mock/f40-build-2144759-50871/root/chroot_tmpdir/scmroot/rust-thiserror'...
$ git fetch origin a6453d24a9ea32dd32365a3107f5e33651a427d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-thiserror
 * [new ref]         a6453d24a9ea32dd32365a3107f5e33651a427d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a6453d2 Update to version 1.0.50; Fixes RHBZ#2245161