Cannot run fbrnch mock on non-release branches

[LecrisUT]

E.g. let's say we are working on a side-tag update and simultaneously updating a few packages in a branch update-foo-x.y. fbrnch mock foo bar baz would fail because we need to specify --release which we cannot pass via fbrnch

$ fbrnch mock

= rust-logos =
Parsing specfile for used sources failed: Could not find release from branch name 'update-0.14.2'. Please specify with --release.
Falling back to downloading all sources.
Could not execute srpm: Could not find release from branch name 'update-0.14.2'. Please specify with --release.
fbrnch: readCreateProcess: fedpkg "srpm" "--define" "_sourcedir /home/lecris/FedoraRPMs/rust-logos" "--define" "_srcrpmdir /home/lecris/rpmbuild/SRPMS" (exit 1): failed

Of course you have other issues here:

• update-0.14.2 is not detected as a branch
• there is no chain-building supported for this command