Rename "master" branch to "main" for glibc 2.35 release.

[Tulio Magno Quites Machado Filho]

Carlos O'Donell via Libc-alpha <libc-alpha@sourceware.org> writes:

> In June 2020 I started this thread for glibc 2.32:
> https://sourceware.org/pipermail/libc-alpha/2020-June/115579.html
> to discuss a branch name change.
>
> Thanks to Paul, Florian, Joseph and DJ who provided feedback on
> the initial discussion.
>
> As of today the default Gitlab new branch is "main" (Gitlab 14 or later).
>
> As of today the default Github new branch is "main".
>
> With Git 2.28+ the default branch name is configurable.
>
> Git has added this advisory text:
> ~~~
>  562 static const char default_branch_name_advice[] = N_(
>  563 "Using '%s' as the name for the initial branch. This default branch name\n"
>  564 "is subject to change. To configure the initial branch name to use in all\n"
>  565 "of your new repositories, which will suppress this warning, call:\n"
>  566 "\n"
>  567 "\tgit config --global init.defaultBranch <name>\n"
>  568 "\n"
>  569 "Names commonly chosen instead of 'master' are 'main', 'trunk' and\n"
>  570 "'development'. The just-created branch can be renamed via this command:\n"
>  571 "\n"
>  572 "\tgit branch -m <name>\n"
> ~~~
>
> My proposal is to rename the development and release branches at the point
> that glibc 2.35 branches:
>
> * master -> main
>
> * release/2.35/master -> release/2.35/main
>
> No alias would be provided for the master branch; we would immediately
> start using 'main' as the development branch.
>
> I am looking for consensus on this proposal.

I also agree with this proposal.

One of the documentation that will be impacted by this change is:
https://www.sourceware.org/glibc/wiki/Development_Todo/Master

I don't think that's meaningful impact for halting this migration, though.

CI systems might need to be modified too, e.g.
https://sourceware.org/git/?p=glibc-buildbot.git;a=blob;f=master.cfg;h=08321a67bbdea7f48989e691e48feeb3c3ead66b;hb=HEAD#l63
Again, I don't think this is a problem.

I'd also like to take the chance and remove branch ibm/master.  It hasn't been
used in years and I don't think it has any historic value.

-- 
Tulio Magno