In function 'nm_uuid_unparse',
      inlined from 'nm_uuid_generate_from_string_str' at src/libnm-glib-aux/nm-uuid.c:393:12,
      inlined from 'nm_uuid_generate_from_strings.constprop' at src/libnm-glib-aux/nm-uuid.c:430:16:
  src/libnm-glib-aux/nm-uuid.h:37:12: error: 'uuid' may be used uninitialized [-Werror=maybe-uninitialized]
     37 |     return nm_uuid_unparse_case(uuid, out_str, FALSE);
        |            ^
  src/libnm-glib-aux/nm-uuid.c: In function 'nm_uuid_generate_from_strings.constprop':
  src/libnm-glib-aux/nm-uuid.c:20:1: note: by argument 1 of type 'const struct NMUuid *' to 'nm_uuid_unparse_case.constprop' declared here
     20 | nm_uuid_unparse_case(const NMUuid *uuid, char out_str[static 37], gboolean upper_case)
        | ^
  src/libnm-glib-aux/nm-uuid.c:390:12: note: 'uuid' declared here
    390 |     NMUuid uuid;
        |            ^
  lto1: all warnings being treated as errors

The problem are code paths with failed g_return*() assertions. Being in
a bad state already, they don't bother to ensure proper return values,
and with LTO the compiler might think there are valid code paths wrongly
handled. Work around.