$ git clone -n https://src.fedoraproject.org/rpms/trojan.git /var/lib/mock/f41-build-834062-158045/root/chroot_tmpdir/scmroot/trojan
Cloning into '/var/lib/mock/f41-build-834062-158045/root/chroot_tmpdir/scmroot/trojan'...
$ git fetch origin dcecfefb4e11bb70acd2585fc6d7b76725abeba6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/trojan
 * [new ref]         dcecfefb4e11bb70acd2585fc6d7b76725abeba6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dcecfef Fix FTBFS (RHBZ#2301338)