The bordeaux build farm depends on computing the derivations on one
machine, then potentially building them on a different machine.

Some of the build machines don't have a new enough guix-daemon that
understands builtin:git-download, so derivations that use this are
sometimes failing (e.g. [1])

1: https://bordeaux.guix.gnu.org/build/10cc5622-6b1f-4f28-ad9a-41cf796d7a15

One potential approach to address this is somehow have the data service
indicate that it wants compatible derivations when computing them,
rather than to have guix do feature detection against the guix-daemon
that is being used at the point the derivations are being computed.