ASAN is out of your way. The following was done outside of Xcode to see if I could show an error, and it was easy if the path was undefined. I assume that Xcode cannot find it where it looks, or, as in the following case, the ASAN path is undefined.
If you try to do this by adding and removing it from your path, the error will disappear, but the line numbers will also disappear, i.e. if you want to see the actual error message again, you need to use
unset ASAN_SYMBOLIZER_PATH
not
ASAN_SYMBOLIZER_PATH=
Create a c program as follows:
int main(void){ int a[3]; a[3] = 4; return 0; }
Compile it, please ignore the warnings ...
gcc -std=c11 -Wall -g3 -fno-omit-frame-pointer -fsanitize=address broken_asan_test.c ./a.out
You should see something like this ...
================================================================= ==29192==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff5ad1052c at pc 0x000104eefe78 bp 0x7fff5ad104f0 sp 0x7fff5ad104e8 WRITE of size 4 at 0x7fff5ad1052c thread T0
Pay attention to this line.
==29192==WARNING: Can't write to symbolizer at fd 3
Change adding character to your path ...
export ASAN_SYMBOLIZER_PATH=/usr/local/Cellar/llvm/3.6.2/bin/llvm-symbolizer
and the error will disappear ...
================================================================= ==29312==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff55ac450c at pc 0x00010a13be78 bp 0x7fff55ac44d0 sp 0x7fff55ac44c8 WRITE of size 4 at 0x7fff55ac450c thread T0