As -Werror is present building gstreamer causes this:

gcc -DHAVE_CONFIG_H -I. -I. -I.. -I/usr/local/include -D_GNU_SOURCE
-DGST_CONFIG_DIR=\"/usr/testing/gstreamer/build/etc/gstreamer\"
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/local/include/libxml2
-D_REENTRANT -D_THREAD_SAFE -I/usr/local/include/glib-2.0
-I/usr/local/lib/glib-2.0/include -I.. -Wall -Werror -D_GNU_SOURCE
-DG_LOG_DOMAIN=g_log_domain_gstreamer
-DGST_CONFIG_DIR=\"/usr/testing/gstreamer/build/etc/gstreamer\" -g -O2 -c
gstqueue.c -Wp,-MD,.deps/libgstreamer_la-gstqueue.TPlo  -fPIC -DPIC -o
.libs/libgstreamer_la-gstqueue.lo
cc1: warnings being treated as errors
gstqueue.c: In function `gst_queue_chain':
gstqueue.c:322: warning: long int format, pthread_t arg (arg 2)
gstqueue.c:324: warning: long int format, pthread_t arg (arg 2)
gstqueue.c: In function `gst_queue_get':
gstqueue.c:477: warning: long int format, pthread_t arg (arg 2)
gstqueue.c:479: warning: long int format, pthread_t arg (arg 2)
gmake[4]: *** [libgstreamer_la-gstqueue.lo] Error 1
gmake[4]: Leaving directory `/usr/testing/gstreamer/gst-cvs/gstreamer/gst'
gmake[3]: *** [all-recursive] Error 1
gmake[3]: Leaving directory `/usr/testing/gstreamer/gst-cvs/gstreamer/gst'
gmake[2]: *** [all] Error 2
gmake[2]: Leaving directory `/usr/testing/gstreamer/gst-cvs/gstreamer/gst'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/usr/testing/gstreamer/gst-cvs/gstreamer'
gmake: *** [all] Error 2