ASAN and UBSAN can't be used together, so at least two run instances needs to be added.

Both will need "-fsanitize=<foo>" in LDFLAGS too,

so this will be:

    CFLAGS="-fsanitize=address -O2 -g" LDFLAGS="-fsanitize=address" ./configure

and

    CFLAGS="-fsanitize=undefined -O2 -g" LDFLAGS="-fsanitize=undefined" ./configure