I'm replacing a hacky Debian package build script with http://jenkins-debian-glue.org/, which uses git-buildpackage.
The generate-git-snapshot script runs this monster of a line:
gbp buildpackage -nc --git-force-create --git-ignore-new --git-ignore-branch -S -us -uc --git-verbose --git-builder=/bin/true --git-cleaner=/bin/true --git-export-dir=
This fails every time with an error: gbp:error: upstream/1.0.0 is not a valid treeish. 1.0.0 is the initial version string in debian/changelog, but the upstream branch doesn't exist.
I'm not quite sure what to do about the upstream branch - this package is not a fork of an existing project, it's a Git repo that's only meant to build a Debian package.
How can/should I build the package?
Unless your packaging is very old, it's probably a 3.0 (quilt) package. If that's the case, gbp is looking for separate branches for upstream source and Debian-specific customizations so that it can prepare the source package correctly.
Since you're building a native package, debian/source/format needs to be changed to 3.0 (native).