I'm trying to link MySQL with a different glibc that provides e.g. a different pthread implementation and actually thought I got it right a few days ago. Obviously, I took notes and wanted to reproduce the outcome but I can't get it to link properly, so I must have forgotten a step.
What I did previously was simply to add the flags pointing to my glibc and the default one second to the cmake command.
GLIBC_FLAGS="-Wl,--rpath=/path/to/my/glibc/build/lib:/usr/lib/x86_64-linux-gnu:/lib/x86_64-linux-gnu -Wl,--dynamic-linker=/path/to/my/glibc/build/lib/ld-linux-x86-64.so.2
cmake \
-DCMAKE_INSTALL_PREFIX=../install \
.. \
-DCMAKE_C_FLAGS="$GLIBC_FLAGS" \
-DCMAKE_CXX_FLAGS="$GLIBC_FLAGS"
These flags work when building a simple a test-program but seem not to work with MySQL as ldd reports the default glibc for mysqld.
$ ldd install/bin/mysqld
linux-vdso.so.1 => (0x00007fff14ffe000)
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f4f1c9bb000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f4f1c7b7000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f4f1c599000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f4f1c295000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f4f1bf91000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f4f1bd7a000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4f1b9b2000)
/lib64/ld-linux-x86-64.so.2 (0x00007f4f1cc13000)
I also tried to set the LD_LIBRARY_PATH and changing the linker flags and lib variables in BUILD/scripts/mysql_config but none of these seem to work.
What is necessary to link MySQL against a different glibc?
After a Kernel-Update, cmake apparently ignored the DCMAKE_CXX_FLAGS and DCMAKE_C_FLAGS if they contained a colon-separated list of paths (the options were used when they contained only a single path).
I worked around this by setting the colon-separated pathlist directly in the CMakeLists.txt in the MySQL root directory.