From: Ben Knoble <ben.knoble@gmail.com>
Date: Mon, 23 Feb 2026 21:41:48 GMT
Subject: Re: [PATCH v6] build: regenerate config-list.h when Documentation changes
Message-ID: <8AB2DD1B-FAFA-4510-82FA-BBD76B442676@gmail.com>
In-Reply-To: <aZv54vN9DdGsvre/@szeder.dev>


> Le 23 févr. 2026 à 01:55, SZEDER Gábor <szeder.dev@gmail.com> a écrit :
> 
> On Sat, Feb 21, 2026 at 09:07:17AM -0500, D. Ben Knoble wrote:
>> The Meson-based build doesn't know when to rebuild config-list.h, so the
>> header is sometimes stale.
>> 
>> For example, an old build directory might have config-list.h from before
>> 4173df5187 (submodule: introduce extensions.submodulePathConfig,
>> 2026-01-12), which added submodule.<name>.gitdir to the list. Without
>> it, t9902-completion.sh fails. Regenerating the config-list.h artifact
>> from sources fixes the artifact and the test.
>> 
>> Since Meson does not have (or want) builtin support for globbing like
>> Make, teach generate-configlist.sh to also generate a list of
>> Documentation files its output depends on, and incorporate that into the
>> Meson build.
>> 
>> We assume that if a user adds a new file under
>> Documentation/config then they will also edit one of the existing files
>> to include that new file, and that will trigger a rebuild. Also mark the
>> generator script as a dependency.
>> 
>> While we're at it, teach the Makefile to use the same "the script knows
>> it's dependencies" logic.
>> 
>> For Meson, combining the following commands helps debug dependencies:
>> 
>>    ninja -C <builddir> -t deps config-list.h
>>    ninja -C <builddir> -t browse config-list.h
>> 
>> The former lists all the dependencies discovered from our output ".d"
>> file (the config documentation) and the latter shows the dependency on
>> the script itself, among other useful edges in the dependency graph.
>> 
>> Helped-by: Patrick Steinhardt <ps@pks.im>
>> Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
>> Signed-off-by: D. Ben Knoble <ben.knoble+github@gmail.com>
>> ---
>> 
>> Notes (benknoble/commits):
>>    Changes from v5 (<611a94cd988e3795bc63dba2f1b270aa0d058bd2.1771425395.git.ben.knoble+github@gmail.com>):
>> 
>>    • Reword a confusing sentence in the commit message
>> 
>> Makefile               |  5 +++--
>> generate-configlist.sh | 11 ++++++++++-
>> meson.build            |  5 ++++-
>> 3 files changed, 17 insertions(+), 4 deletions(-)
>> 
>> diff --git a/Makefile b/Makefile
>> index 7f37ad8f58..6f926ffb1f 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -2688,9 +2688,10 @@ $(BUILT_INS): git$X
>>    cp $< $@
>> 
>> config-list.h: generate-configlist.sh
>> +    @mkdir -p .depend
>> +    $(QUIET_GEN)$(SHELL_PATH) ./generate-configlist.sh . $@ .depend/config-list.h.d
>> 
>> -config-list.h: Documentation/*config.adoc Documentation/config/*.adoc
>> -    $(QUIET_GEN)$(SHELL_PATH) ./generate-configlist.sh . $@
>> +-include .depend/config-list.h.d
> 
> This breaks the build when something disappears from
> Documentation/config/:
> 
>  $ git checkout origin/seen
>  HEAD is now at 57edfa3ce8 Merge branch 'ty/setup-error-tightening' into seen
>  $ ls -l Documentation/config/hook.adoc
>  -rw-rw-r-- 1 szeder szeder 3828 Feb 23 07:50 Documentation/config/hook.adoc
>  $ git grep hook.adoc
>  Documentation/git-hook.adoc:include::config/hook.adoc[]
>  Documentation/howto/meson.build:  'rebuild-from-update-hook.adoc',
>  Documentation/meson.build:  'git-hook.adoc' : 1,
>  $ make V=1 config-list.h
>  /bin/sh ./generate-configlist.sh . config-list.h .depend/config-list.h.d
>  $ git checkout 0aabf70f60
>  Previous HEAD position was 57edfa3ce8 Merge branch 'ty/setup-error-tightening' into seen
>  HEAD is now at 0aabf70f60 build: regenerate config-list.h when Documentation changes
>  $ ls -l Documentation/config/hook.adoc
>  ls: cannot access 'Documentation/config/hook.adoc': No such file or directory
>  $ git grep hook.adoc
>  Documentation/howto/meson.build:  'rebuild-from-update-hook.adoc',
>  Documentation/meson.build:  'git-hook.adoc' : 1,
>  $ make V=1 config-list.h
>  GIT_VERSION=2.53.0.119.g0aabf70f60
>  make: *** No rule to make target 'Documentation/config/hook.adoc', needed by 'config-list.h'.  Stop.
>  $ grep hook.adoc .depend/config-list.h.d
>  config-list.h: ./Documentation/config/hook.adoc

Indeed. This might arise while bisecting, which was my original motivation. Thoughts on a path forward? At least this issue (to me) is clearer than a spurious test failure :)