Hello 

thank you very much Hubert for your report: errors like the one you
found (packages build failures) are bugs, next time please report them
to bug-guix@gnu.org; better to close a non-bug than to miss an actual
one ;-)

As you can see I've now filed a new bug: bug#63551

Thank you also to Vagrant and Denis for the heads up, please submit
further comments or patches to 63551@debbugs.gnu.org

Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org> writes:

[...]

> There are several approaches here and I've patches for two of them if
> needed (I've attached them):
> (1) backport some upstream patches:
>     - There are 2 catch2 updates, they can be squashed into 1 patch
>     - We also need a patch for fixing unused variables.
> (2) Update cpp-mustache: There is an upstream commit
>     (https://github.com/kainjow/Mustache/commit/4ed8c0b5a2a43d59394bd6900dc04e738dbf8c02)
>     that change some version string. I've asked upstream if that was
>     the 5.0.0 release but so far I got no answer.
>     https://github.com/kainjow/Mustache/issues/65
>
> (1) is 0001-gnu-cpp-mustache-fix-build-with-newer-glibc.patch
> (2) is 0001-bug-reported-upstream-for-release-info-gnu-cpp-musta.patch
>
> I didn't share the patches yet because I was waiting on upstream to
> clarify the situation with the lack of 5.0.0 tag.

Please do not wait for an official upstream "release" (git tag,
actually) for cpp-mustache, I guess upstream just forgot to tag it: Guix
is full of "not officially" released or properly tagged packages,
sources are often taken from carefully selected git commits (I've
recently proposed a patch for dia, that is in a very similar situation)

Since commit 4ed8c0b is setting version to 5.0.0 and that version works
(does it?), I'd go for an "update to 5.0.0" patch

My two cents.

[...]

Happy hacking! Gio'

-- 
Giovanni Biscuolo

Xelera IT Infrastructures