$ git clone -n https://src.fedoraproject.org/rpms/rust-gethostname.git /var/lib/mock/f39-build-1521679-35855/root/chroot_tmpdir/scmroot/rust-gethostname
Cloning into '/var/lib/mock/f39-build-1521679-35855/root/chroot_tmpdir/scmroot/rust-gethostname'...
$ git fetch origin 101937272af1e451f908c394546d2953690a5424:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gethostname
 * [new ref]         101937272af1e451f908c394546d2953690a5424 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1019372 Update to version 0.4.3; Fixes RHBZ#2133308