Gstreamer-sys: test failed on fedora copr

https://download.copr.fedorainfracloud.org/results/remilauzier/gtk/fedora-34-x86_64/02312091-rust-gstreamer-sys/builder-live.log.gz

tests/layout.c: In function 'main':
tests/layout.c:49:52: error: 'GstCustomMeta' undeclared (first use in this function)
   49 |     printf("%s;%zu;%zu\n", "GstCustomMeta", sizeof(GstCustomMeta), alignof(GstCustomMeta));
      |                                                    ^~~~~~~~~~~~~
tests/layout.c:49:52: note: each undeclared identifier is reported only once for each function it appears in
tests/layout.c:71:50: error: 'GstGapFlags' undeclared (first use in this function); did you mean 'GstMapFlags'?
   71 |     printf("%s;%zu;%zu\n", "GstGapFlags", sizeof(GstGapFlags), alignof(GstGapFlags));
      |                                                  ^~~~~~~~~~~
      |                                                  GstMapFlags
tests/layout.c:144:56: error: 'GstSerializeFlags' undeclared (first use in this function)
  144 |     printf("%s;%zu;%zu\n", "GstSerializeFlags", sizeof(GstSerializeFlags), alignof(GstSerializeFlags));
      |                                                        ^~~~~~~~~~~~~~~~~