Bug#888422: libmpfr6 should add Breaks: libmpfr4

[Adrian Bunk <bunk@debian.org>]

Control: tags -1 - moreinfo

On Thu, Jan 25, 2018 at 07:39:27PM +0100, Julien Cristau wrote:
> Control: severity -1 normal
> Control: tag -1 moreinfo
> 
> On Thu, Jan 25, 2018 at 14:11:49 +0200, Adrian Bunk wrote:
> 
> > Package: libmpfr6
> > Version: 4.0.0-5
> > Severity: serious
> > 
> > Mixing libmpfr4 and libmpfr6 doesn't work well:
> > 
> > flint-arb FTBFS with:
> > /usr/bin/ld: warning: libmpfr.so.4, needed by /usr/lib/libflint.so, may conflict with libmpfr.so.6
> > /usr/bin/ld: mpfr_free_func: TLS definition in //usr/lib/x86_64-linux-gnu/libmpfr.so.4 section .tbss mismatches non-TLS definition in /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/libmpfr.so section .text
> > //usr/lib/x86_64-linux-gnu/libmpfr.so.4: error adding symbols: Bad value
> > collect2: error: ld returned 1 exit status
> > 
> > Some packages like fractalnow FTBFS when gcc and libmpc3 use
> > different mpfr libraries, with a gcc ICE:
> > ../../src/init2.c:52: MPFR assertion failed: p >= 2 && p <= ((mpfr_prec_t)((mpfr_uprec_t)(~(mpfr_uprec_t)0)>>1))
> > src/fractal_compute_engine.c: In function 'FractalLoopMANDELBROTPINTAVERAGECOLORINGDISCRETECURVATURENONESINGLE':
> > src/fractal_compute_engine.c:285:1: internal compiler error: Aborted
> > 
> > It is not even obvious in the latter case that this is always only an ICE,
> > and not sometimes a miscompilation.
> > 
> > The libmpc3 issue is also expected to hit users who have older gcc versions
> > still installed, e.g. gcc-6 still installed after stretch->buster upgrade.
> > 
> > When the dependencies are fulfilled users can expect to have working software,
> > even a forced removal on stretch->buster upgrades is better than runtime problems.
> 
> Is this actually a problem between libmpfr4 and libmpfr6, or libmpfr4
> and the new libmpfr-dev?
>...

This is a problem between libmpfr4 and libmpfr6.

libmpfr-dev is not installed when gcc ICEs building mathgl.[1,2]

> Cheers,
> Julien

cu
Adrian

[1] https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/mathgl.html
[2] reproducible uses a slightly patched gcc, but I've reproduced this
    FTBFS with the normal (older libmpfr4-using) gcc

-- 

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