ASAN: debug build fails

[maleadt]

Trying to make a debug build of Julia under ASAN I'm running into:

ERROR: Unable to load dependent library libjulia-internal-debug.so.1
Message: libjulia-internal-debug.so.1: undefined symbol: __libc_siglongjmp

Use of this symbol was introduced by @Keno in #46336, and is intended to bypass the ASAN hook and directly call siglongjmp from glibc. I'm not sure why it isn't working; @vtjnash commented that this symbol has been named like that for 25 years. Disabling the redefinition and just using siglongjmp works around the compilation error.

objdump output:

objdump -t libjulia-internal-debug.so.1 | grep siglong
0000000000000000       F *UND*  0000000000000000              siglongjmp@GLIBC_2.2.5
0000000000000000         *UND*  0000000000000000              __libc_siglongjmp

[topolarity]

On my system (Ubuntu 22.04), the symbol is still present in libc (you can see it in the objdump output of libc.so.6) but it's not published to the symbol tables.

I expect it's intended not to be exported, and we need to find another way to bypass the interceptor for siglongjmp