Re: [Buildroot] [PATCH v4 2/3] package/util-linux: libuuid needs MMU

From: Julien Olivain via buildroot <buildroot@buildroot.org>
To: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: buildroot@buildroot.org,
	"Marcin Niestroj" <m.niestroj@grinn-global.com>,
	"Rahul Bedarkar" <rahulbedarkar89@gmail.com>,
	"Petr Vorel" <petr.vorel@gmail.com>,
	"Fabrice Fontaine" <fontaine.fabrice@gmail.com>,
	"Kurt Van Dijck" <dev.kurt@vandijck-laurijssen.be>,
	"Grzegorz Blach" <grzegorz@blach.pl>,
	"José Luis Salvador Rufo" <salvador.joseluis@gmail.com>,
	"Philippe Proulx" <eeppeliteloop@gmail.com>,
	"Brandon Maier" <brandon.maier@collins.com>,
	"Luca Ceresoli" <luca.ceresoli@bootlin.com>,
	"Chen Pei" <cp0613@linux.alibaba.com>,
	"Sergio Prado" <sergio.prado@e-labworks.com>,
	"Alistair Francis" <alistair@alistair23.me>,
	"Eric Le Bihan" <eric.le.bihan.dev@free.fr>,
	"Bernd Kuhls" <bernd@kuhls.net>, "Gao Xiang" <hsiangkao@aol.com>,
	"Giulio Benetti" <giulio.benetti@benettiengineering.com>,
	"Etienne Carriere" <etienne.carriere@foss.st.com>
Subject: Re: [Buildroot] [PATCH v4 2/3] package/util-linux: libuuid needs MMU
Date: Wed, 22 Jul 2026 19:48:46 +0200	[thread overview]
Message-ID: <dfc5d409468f05cd4f3e8350f72aeaaa@free.fr> (raw)
In-Reply-To: <20260721125337.2537436-2-dario.binacchi@amarulasolutions.com>

Hi Dario, all,

On 21/07/2026 14:53, Dario Binacchi wrote:
> When building util-linux with libuuid enabled on noMMU targets
> (e.g., bootlin-armv7m-uclibc or bootlin-m68k-5208-uclibc), the build
> fails with the following error:
> 
> libuuid/src/gen_uuid.c: In function ‘uuid_generate_time_generic’:
> libuuid/src/gen_uuid.c:629:17: error: implicit declaration of function 
> ‘pthread_atfork’; did you mean ‘pthread_join’? 
> [-Wimplicit-function-declaration]
>   629 |                 pthread_atfork(NULL, NULL, reset_uuidd_cache);
>       |                 ^~~~~~~~~~~~~~
>       |                 pthread_join
> 
> This happens because pthread_atfork() is not available on noMMU
> configurations as reported by commit 59fe7547a495 ("package/libcap-ng:
> disable pthread support on nommu").
> 
> Fix this by adding a dependency on BR2_USE_MMU to libuuid. As a
> consequence, also propagate the BR2_USE_MMU dependency to all packages
> selecting BR2_PACKAGE_UTIL_LINUX_LIBUUID to prevent "unmet direct
> dependencies" Kconfig errors.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

I see we fixed this kind of issue in the past, in commit:
https://gitlab.com/buildroot.org/buildroot/-/commit/8489cb0932b6ca00104dab3bd54e76d1bcf6c65c

But apparently, the failing toolchains include a libpthread which
gets detected by util-linux configure script. I'm not sure when this
broke again.

There was this proposal too:
https://patchwork.ozlabs.org/project/buildroot/patch/20260426102215.3100043-1-bernd@kuhls.net/

But I'd prefer to not include this patch and try to make libuuid
work on noMMU, since upstream is supposed to support it. We can fix
util-linux this in another patch.

The rest of the series looks good, so I might just remove the
BR2_USE_MMU dependency when applying.

Best regards,

Julien.
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