I would like to rebuild the Debian package 'postfix'. Without anything fancy, so no local patches and unsigned packages are fine.
Here's what I tried:
Install some dependencies:
$ apt install fakeroot git-buildpackage $ apt build-dep postfix
(Postfix on my build machine is the same/similar available as version I'm trying to build, so this should install most of the build dependencies just fine. I don't have any build dependency issue as well.)
Clone the Debian sources:
$ git clone https://salsa.debian.org/postfix-team/postfix-dev.git
At the time of writing this points to c21140525af28be0e1bacd932e85b96babe6ca98 (tag: v3.3.2-4).
cd into the clone:
$ cd postfix-dev
IIUC, I should now be able to build the package with a command like
$ gbp buildpackage -uc -us
(With the two options to make unsigned packages.)
However, the last step results in the error:
gbp:error: upstream/3.3.2 is not a valid treeish