Variable length array in structure won't be supported - Rebuild of the Debian archive with clang

"Variable length array in structure won't be supported" build failure(s) — clang 6.0

int returnAnInt(void) {
  return 42;
}

int main() {
  struct {
     char buf[returnAnIt()];
  } r;
}

Package	Version	Supposed error message	Full log
bird	1.6.4-1	netlink.c:942:10: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
libdc1394-22	2.2.5-1	control.c:286:19: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
linux	4.15.17-1	ore.c:153:28: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
ndisc6	1.0.3-3	trace-tcp.c:57:11: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
rng-tools	2-unofficial-mt.14-1	rngd_linux.c:191:17: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
rng-tools5	5-2	rngd_linux.c:126:17: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
unicap	0.9.12+repack20150328.0.git2c600ae-2	dcam_juju_capture.c:286:12: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
unscd	0.53-1	nscd.c:2448:9: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log
user-mode-linux	4.15-1um-1	fs/exofs/ore.c:153:28: error: fields must have a constant size: 'variable length array in structure' extension will never be supported	Log

9 errors