using GNU libc 2.27

[Vincent Lefevre]

On 2026-04-20 10:25:59 +0200, Paul Zimmermann wrote:
> I'd like to use GNU libc 2.27 with the CORE-MATH test suite. Some time ago
> I got the following help from this list:
> 
> # to check the GNU libc 2.27, installed in say /tmp:
> #     CORE_MATH_CHECK_STD=true CORE_MATH_LAUNCHER="/tmp/lib/ld-2.27.so --library-path /tmp/lib" LDFLAGS="-L /tmp/lib" ./check.sh --worst --rndn exp
> 
> I tried again and it fails (Debian Linux, with gcc 15.2.0) because MPFR needs
> __isoc23_strtol:
> 
> zimmerma@coriandre:~/svn/core-math$ CFLAGS=-DCORE_MATH_NO_OPENMP OMP_NUM_THREADS=1 CORE_MATH_CHECK_STD=true CORE_MATH_LAUNCHER="$TMP/lib/ld-2.27.so --library-path $TMP/lib" LDFLAGS="-L $TMP/lib" ./check.sh --worst --rndn exp
> /usr/bin/x86_64-linux-gnu-ld.bfd: check_worst.o: in function `readstdin':
> check_worst_uni.c:(.text+0x202): undefined reference to `__isoc23_sscanf'
> /usr/bin/x86_64-linux-gnu-ld.bfd: /usr/lib/gcc/x86_64-linux-gnu/15/../../../x86_64-linux-gnu/libmpfr.so: undefined reference to `__isoc23_strtol@GLIBC_2.38'
> collect2: error: ld returned 1 exit status
> gmake: *** [../support/Makefile.univariate:12: check_worst] Error 1
> 
> I recompiled GMP and MPFR with -std=c99, installed them in /tmp and tried
> again, but now it seems the system ld needs __isoc23_strtol:
> 
> zimmerma@coriandre:~/svn/core-math$ CFLAGS="-I /tmp/include -std=c99 -DCORE_MATH_NO_OPENMP" OMP_NUM_THREADS=1 CORE_MATH_CHECK_STD=true CORE_MATH_LAUNCHER="$TMP/lib/ld-2.27.so --library-path $TMP/lib" LDFLAGS="-L /tmp/lib -L $TMP/lib" ./check.sh --worst --rndn exp
> /usr/bin/x86_64-linux-gnu-ld.bfd: /tmp/lib/libgmp.so.10: undefined reference to `__isoc23_strtol@GLIBC_2.38'

If I undetstand correctly, you need to recompile GMP and MPFR also
against glibc 2.27, as it seems that they are currently expecting
at least glibc 2.38.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)