$ git clone -n https://src.fedoraproject.org/rpms/rust-gethostname0.2.git /var/lib/mock/f41-build-side-1-3124906-39482/root/chroot_tmpdir/scmroot/rust-gethostname0.2
Cloning into '/var/lib/mock/f41-build-side-1-3124906-39482/root/chroot_tmpdir/scmroot/rust-gethostname0.2'...
$ git fetch origin 8f9fba11abb785c37c87e1f46f7193133237d044:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gethostname0.2
 * [new ref]         8f9fba11abb785c37c87e1f46f7193133237d044 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8f9fba1 compat package no longer needed