I'm trying to install XFCE 4.4 but the installer errors out, here is a copy from the error log.

exo-mount-point.c: In function `exo_mount_point_list_match_active':
exo-mount-point.c:264: error: dereferencing pointer to incomplete type
exo-mount-point.c:272: error: invalid use of undefined type `struct statfs'
exo-mount-point.c:272: error: dereferencing pointer to incomplete type
exo-mount-point.c:272: error: invalid use of undefined type `struct statfs'
exo-mount-point.c:272: error: dereferencing pointer to incomplete type
exo-mount-point.c:273: error: invalid use of undefined type `struct statfs'
exo-mount-point.c:273: error: dereferencing pointer to incomplete type
exo-mount-point.c:273: error: invalid use of undefined type `struct statfs'
exo-mount-point.c:273: error: dereferencing pointer to incomplete type
 gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -DDATADIR=\"/usr/pkg/share\" -DEXO_COMPILATION -DG_LOG_DOMAIN=\"exo\" -DLIBEXECDIR=\"/usr/pkg/libexec\" -DLIBEXO_VERSION_API=\"0.3\" -DPACKAGE_LOCALE_DIR=\"/usr/pkg/share/locale\" -I/usr/pkg/include -I/usr/X11R6/include -I/usr/pkg/include -DHAVE_GNUC_VISIBILITY -O2 -DXTHREADS -I/usr/pkg/include/gtk-2.0 -I/usr/pkg/lib/gtk-2.0/include -I/usr/pkg/include/atk-1.0 -I/usr/pkg/include/cairo -I/usr/pkg/include/pango-1.0 -I/usr/pkg/include -I/usr/X11R6/include -I/usr/pkg/include/glib/glib-2.0 -I/usr/pkg/lib/glib-2.0/include -I/usr/pkg/include/freetype2 -I/usr/pkg/include/libpng12 -I/usr/pkg/include/xfce4 -I/usr/pkg/include/glib/glib-2.0 -I/usr/pkg/lib/glib-2.0/include -I/usr/pkg/include -I/usr/X11R6/include -I/usr/pkg/include -DNDEBUG -DG_DISABLE_CAST_CHECKS -DG_DISABLE_ASSERT -DG_DISABLE_CHECKS -MT libexo_0_3_la-exo-icon-view.lo -MD -MP -MF .deps/libexo_0_3_la-exo-icon-view.Tpo -c exo-icon-view.c -o libexo_0_3_la-exo-icon-view.o >/dev/null 2>&1
gmake[3]: *** [libexo_0_3_la-exo-mount-point.lo] Error 1
gmake[3]: *** Waiting for unfinished jobs....
gmake[3]: Leaving directory `/home/temp/xfce4-4.4.0-installer/exo/exo'
gmake[2]: *** [all] Error 2
gmake[2]: Leaving directory `/home/temp/xfce4-4.4.0-installer/exo/exo'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/home/temp/xfce4-4.4.0-installer/exo'
gmake: *** [all] Error 2
!! Failed to build exo, see the errors above
!! for details on the problem.