Bug#770940: error: ‘lgamma_r’ was not declared in this scope

[Mathieu Malaterre <malat@debian.org>]

Package: libc6-dev
Version: 2.19-13
Severity: important

I cannot compile the following pseudo code (see attachment) it fails with:

$ g++ -ffast-math foo.cxx
In file included from /usr/include/math.h:432:0,
                 from foo.cxx:3:
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘double
lgamma(double)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:260:41: error:
‘lgamma_r’ was not declared in this scope
   return lgamma_r (__d, &__local_signgam);
                                         ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘float
lgammaf(float)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:269:42: error:
‘lgammaf_r’ was not declared in this scope
   return lgammaf_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘long
double lgammal(long double)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:279:42: error:
‘lgammal_r’ was not declared in this scope
   return lgammal_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘double
gamma(double)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:293:41: error:
‘lgamma_r’ was not declared in this scope
   return lgamma_r (__d, &__local_signgam);
                                         ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘float
gammaf(float)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:302:42: error:
‘lgammaf_r’ was not declared in this scope
   return lgammaf_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function ‘long
double gammal(long double)’:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:312:42: error:
‘lgammal_r’ was not declared in this scope
   return lgammal_r (__d, &__local_signgam);

thanks.

#include <errno.h>
#undef __USE_MISC
#include <math.h>

int main(){}