$ git clone -n https://src.fedoraproject.org/rpms/rust-sha1.git /var/lib/mock/f38-build-side-42-init-devel-1395801-31050/root/chroot_tmpdir/scmroot/rust-sha1
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1395801-31050/root/chroot_tmpdir/scmroot/rust-sha1'...
$ git fetch origin d8e29fa7e6cf6bf66c1bf637efc915c47c00e4dd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-sha1
 * [new ref]         d8e29fa7e6cf6bf66c1bf637efc915c47c00e4dd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d8e29fa Update to version 0.10.6; Fixes RHBZ#2240045