first sed: because MD_CONFIGURE calls scripts/configure.sh, with parameter gen-buildinfo.
Even if I add the scripts directory to the tarball as well, it would still give trouble:
https://github.com/mono/monodevelop/blob/master/scripts/configure.cs#L163 checks for the git revision (git rev-parse HEAD), and that would not work in the tarball, because it is not a git working tree?

second sed: If no build/bin/buildinfo file exists, because the MD_CONFIGURE line is commented, then another step fails because it expects the file to exist. So I just touch it. I cannot find that place at the moment... need to go...