$ git clone -n https://src.fedoraproject.org/rpms/rust-iana-time-zone.git /var/lib/mock/f39-build-1521793-35859/root/chroot_tmpdir/scmroot/rust-iana-time-zone
Cloning into '/var/lib/mock/f39-build-1521793-35859/root/chroot_tmpdir/scmroot/rust-iana-time-zone'...
$ git fetch origin b6da85acec2bb1108f395b820091ec60fcf54c9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-iana-time-zone
 * [new ref]         b6da85acec2bb1108f395b820091ec60fcf54c9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b6da85a Update to version 0.1.58; Fixes RHBZ#2244647