libasan.so is not a thing. libclang-rt.asan-ARCH.so is the asan DSO and it is not linked by default. Search for __asan_init instead.
MODIFY
src/afl-fuzz-init.c
src/afl-fuzz-init.c
@@ -2014,7 +2014,7 @@ void check_binary(afl_state_t *afl, u8 *fname) {
}
- if (memmem(f_data, f_len, "libasan.so", 10) ||
+ if (memmem(f_data, f_len, "__asan_init", 11) ||
memmem(f_data, f_len, "__msan_init", 11))
afl->fsrv.uses_asan = 1;

libasan.so is not a thing. libclang-rt.asan-ARCH.so is the asan DSO and it is not linked by default. Search for __asan_init instead.