mpfr-3.0 breaks real_mpfr.pyx

[kiwifb]

After updating everything to mpfr-3.0 I got a nasty doctest failure:

francois@vrooom ~ $ sage -t  -force_lib "devel/sage/sage/rings/real_mpfr.pyx"
sage -t -force_lib "devel/sage/sage/rings/real_mpfr.pyx"    


------------------------------------------------------------
Unhandled SIGSEGV: A segmentation fault occured in Sage.
This probably occured because a *compiled* component
of Sage has a bug in it (typically accessing invalid memory)
or is not properly wrapped with _sig_on, _sig_off.
You might want to run Sage under gdb with 'sage -gdb' to debug this.
Sage will now terminate (sorry).
------------------------------------------------------------


         [5.5 s]
 
----------------------------------------------------------------------
The following tests failed:


        sage -t -force_lib "devel/sage/sage/rings/real_mpfr.pyx"
Total time for all tests: 5.5 seconds

The hunt revealed that the failure comes from this particular test:

sage: R = RealField(2147483647)


------------------------------------------------------------
Unhandled SIGSEGV: A segmentation fault occured in Sage.
This probably occured because a *compiled* component
of Sage has a bug in it (typically accessing invalid memory)
or is not properly wrapped with _sig_on, _sig_off.
You might want to run Sage under gdb with 'sage -gdb' to debug this.
Sage will now terminate (sorry).
------------------------------------------------------------

It could be caused by some memory constraint on my machine,
may be mpfr uses more memory. This particular value is 2^31-1 and
is meant to be the maximum precision that can be set for mpfr.
A few test show that on my machine the correct value is 2^31-2^5,
that is 2^31-2^5+1 leads to the segfault while the previous value is safe.

[cschwan]

Same here on x86 - looks like Sage needs some work on it

[cschwan]

Works fine on amd64.

[kiwifb]

http://trac.sagemath.org/sage_trac/ticket/11666 not ready for inclusion as the 32bit issue is still not resolved.

[burcin]

#11666 was merged in Sage-5.0.beta7. I guess this issue can be closed.

[kiwifb]

I'll close it when 5.0 becomes "stable". In the main time I am keeping it open so people using 4.8 don't find it and open an issue for it. We could always backport it to sage-4.8 if 5.0 takes too long I guess.

[kiwifb]

OK, as promised I am closing this. I'll probably purge sage 4.8 next week somewhere in my increasingly insane schedule.