Re: Next steps from GTI TAC meeting on 2023-03-08 - Evaluate cost of glibc migration.

On 5/24/23 14:46, Joseph Myers wrote:
> On Wed, 24 May 2023, Carlos O'Donell wrote:
> 
>> If we removed all the hooks, what is the consequence of a commit that is 
>> wrong? Can we just fix the sources with a subsequent commit? Add a 
>> light-weight linting check in 'make check' that additionally reports 
>> this?
> 
> The consequence, at least for GCC, is that other scripting that depends on 
> certain invariants of commits falls over.  Mapping from SVN revisions to 
> git commits relies on only a single commit matching a given From-SVN 
> commit message pattern rather than such a commit message getting quoted in 
> another commit message in a way that confuses the mapping.  ChangeLog 
> generation falls over if there are various problems with commit contents 
> or messages.
Thanks, both of those seem like they are surmountable challenges:

(a) The community may choose not to support SVN/CVS legacy repositories.

(b) You already need a ChangeLog post-process to fix issues, so the hook is
    a belt-and-suspenders way to reduce the work done by global maintainers to
    keep the ChangeLog clean.

Just a reminder that we are talking about the cost of the glibc migration, but have
also started discussing the gcc migration which is more complex.

(1) CVS/SVN read-only repositories.

If the GCC community decides not to keep the read-only CVS and SVN repositories in
favour of the git repository with all the currently converted history, then does
this remove some of the more complex git hooks?

(2) Changelog invariant checking.

ChangeLog generation as I understand it is a concatenation of the commit message
ChangeLog snippet (Nightly update_version_git), and already would need manual editing
if someone makes a mistake e.g. 32582c190b91287a0d1239162333f5ad0ac81e72 in gcc where
Jakub adjusts the entries? Does dropping this hook create more work for you and Jakub
and Richie to udpate malformed ChangeLog entries for the day? Who gets email if the
update fails?

-- 
Cheers,
Carlos.