$ git clone -n https://src.fedoraproject.org/rpms/rust-log.git /var/lib/mock/f39-build-1523134-35986/root/chroot_tmpdir/scmroot/rust-log
Cloning into '/var/lib/mock/f39-build-1523134-35986/root/chroot_tmpdir/scmroot/rust-log'...
$ git fetch origin 1b40f91cf43aecb7bf191b09fcd9a1f94c129609:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-log
 * [new ref]         1b40f91cf43aecb7bf191b09fcd9a1f94c129609 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b40f91 Update to version 0.4.20; Fixes RHBZ#2231609