Build system issues make building GNU hello from git hard

[Matthew Vernon]

Hi,

I wanted an example piece of software for a tutorial on packaging 
upstream software from git for binary .debs, and figured GNU Hello would 
be a good choice. I'm afraid the experience of building from a git tag 
(i.e. clone the repo, check out the tag of the release you want to 
build, build) is quite hostile; I found three key problems:

1) bootstrap installs git hooks that reject commit messages

I appreciate that for patches sent upstream you have coding standards, 
but the commit-message hook is confusing for newcomers, and particularly 
interacts badly with e.g. emacs' git mode (if you commit a message from 
within emacs that the hook doesn't like your emacs spins indefinitely; 
and then recovery is hard because the hook will look for the editor 
configured in git, so even if you do EDITOR=nano git commit to try and 
un-wedge things, it still tries to launch emacsclient if the commit 
message wasn't right.

2) gnulib is used as a git submodule

This adds unnecessary complexity to the build process, and requires 
special handling in CI too. Further, it's not necessary to use gnulib 
thus (e.g. man-db doesn't use it as a submodule), and submodules aren't 
really best practice (cf https://diziet.dreamwidth.org/14666.html which 
expounds on their limitations at length)

3) tests erroneously fail inside CI

I've made no modifications to gnulib, but my CI (inside gitlab, using 
GIT_SUBMODULE_STRATEGY: recursive ) fails because the test code thinks 
I've modified something in the submodule - the failing code is:

git submodule --quiet foreach                                   \
      'test "$(git rev-parse "$sha1")"                      \
          = "$(git merge-base origin "$sha1")"'             \
    || { echo 'maint.mk: found non-public submodule commit' >&2; \
         exit 1; };     

You can see a full build log here (error at the bottom):

https://gitlab.wikimedia.org/repos/data_persistence/matthewvernon-demo-hello/-/jobs/150946

It's hard to make headway on fixing that because the actual outputs from 
git rev-parse and git merge-base aren't emitted, and maint.mk is inside 
the submodule (which I can't edit without falling foul of that check for 
real).

Likewise, I can get my package to build by skipping the tests, but 
that's not really ideal for a tutorial showing how things should be done :)

Sorry to be picky about build systems, but GNU Hello does describe 
itself as an example of best development practice, and I think given 
that it ought to be more straightforward to build it from a git checkout.

Thanks for your consideration,

Matthew