$ git clone -n https://src.fedoraproject.org/rpms/Singular.git /var/lib/mock/f39-build-2257177-54308/root/chroot_tmpdir/scmroot/Singular
Cloning into '/var/lib/mock/f39-build-2257177-54308/root/chroot_tmpdir/scmroot/Singular'...
$ git fetch origin f35612dc800be8ab79b73f049691f8f627e15818:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/Singular
 * [new ref]         f35612dc800be8ab79b73f049691f8f627e15818 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f35612d Backport upstream patch to fix C99 compatibility issue