Building xfconf against glib2-2.30.2: 

make[3]: Entering directory `/builddir/build/BUILD/xfconf-4.9.1/xfconfd'
  CC     xfconfd-main.o
  CC     xfconfd-xfconf-backend.o
  CC     xfconfd-xfconf-backend-factory.o
  CC     xfconfd-xfconf-daemon.o
  CC     xfconfd-xfconf-locking-utils.o
  CC     xfconfd-xfconf-backend-perchannel-xml.o
  CC     xfconfd-xfconf-types.o
  GEN    org.xfce.Xfconf.service
  CCLD   xfconfd
/usr/lib/gcc/x86_64-redhat-linux/4.6.3/../../../../lib64/libxfce4util.so: undefined reference to `g_mutex_unlock'
/usr/lib/gcc/x86_64-redhat-linux/4.6.3/../../../../lib64/libxfce4util.so: undefined reference to `g_mutex_lock'
collect2: ld returned 1 exit status

The configure/autotools check has: 

configure.ac:XDT_CHECK_PACKAGE([GLIB], [gobject-2.0], [2.24.0])

Perhaps this should be bumped to 2.32?