From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: [PATCH] core-updates: qtbase fails to compile on Linux < 3.17
Date: Mon, 04 Jun 2018 13:33:22 +0200
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In-Reply-To: <87zi0eoij4.fsf@mdc-berlin.de> (Ricardo Wurmus's message of "Fri,
	1 Jun 2018 13:25:57 +0200")
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To: Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>
Cc: guix-devel@gnu.org

Hello!

Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de> skribis:

> qtbase sometimes fails to build on core-updates.  I now know that it
> only fails on Linux < 3.17, which is why I=E2=80=99ve seen the failure on=
ly on
> RHEL6 and RHEL7 systems with Linux 2.6.32 and 3.10, respectively.

Good catch!

> With the attached patch, qtbase builds on all supported kernels as the
> minimum kernel version becomes 2.6.28, which is lower than the minimum
> for glibc.
>
> It disables code that depends on the =E2=80=9Cgetentropy=E2=80=9D and =E2=
=80=9Crenameat2=E2=80=9D
> syscalls.  Qtbase has a fallback implementation for random things when
> getentropy is not available.  See src/corelib/global/qrandom.cpp for
> more information.

I=E2=80=99m late to the party but I think it=E2=80=99s OK.

I think a better fix would be for Qt to handle ENOSYS correctly, which
presumably is what happens on these old kernels.  I suppose it=E2=80=99s al=
so
more difficult to achieve=E2=80=A6

Ludo=E2=80=99.