
We used COMPILER_FLAG(LIBSYSTEMD_NM_CFLAGS, "-Wno-gnu-variable-sized-type-not-at-end") to detect whether the flag is supported. However, that does not work with GCC since version 4.4 due to https://gcc.gnu.org/wiki/FAQ#wnowarning. Note that we already had NM_COMPILER_WARNING(), but that again does something rather different.