Installing diffuse or meld - failure, can't install pygtk

Tried to install diffuse today.  Had to first install pygtk.  pygtk requires glib.  glib doesn't install defaultly.

To install glib, downloaded it (which wasn't easy, required xz too) and ran this command:

PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/local/lib/pkgconfig/ ./configure

glib install worked, now pygobject fails:

checking for GLIB - version >= 2.8.0... yes (version 2.35.2)
checking for PYGOBJECT... no
configure: error: Package requirements (pygobject-2.0 >= 2.21.3) were not met:

Requested 'pygobject-2.0 >= 2.21.3' but version of PyGObject is 2.18.0

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

pygobject requires gobject-introspection:

http://ftp.gnome.org/pub/GNOME/sources/gobject-introspection/1.31/

do this again:

PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/local/lib/pkgconfig/ ./configure

make -j 4'

failure:

  CC     glib_print-glib-print.o

make[2]: *** No rule to make target `/glib-2.0/include/glibconfig.h', needed by `GLib-2.0.gir'.  Stop.

make[2]: *** Waiting for unfinished jobs....

examples/glib-print.c: In function 'main':

examples/glib-print.c:11: warning: 'g_type_init' is deprecated (declared at /usr/local/include/glib-2.0/gobject/gtype.h:669)

girepository/gi-dump-types.c: In function 'main':

girepository/gi-dump-types.c:12: warning: 'g_type_init' is deprecated (declared at /usr/local/include/glib-2.0/gobject/gtype.h:669)

make[1]: *** [all-recursive] Error 1

make: *** [all] Error 2

make -> failure again:

  GEN    g-ir-doc-tool

make[2]: *** No rule to make target `/glib-2.0/include/glibconfig.h', needed by `GLib-2.0.gir'.  Stop.

make[1]: *** [all-recursive] Error 1

make: *** [all] Error 2

well, I give up.

Installing qt on 10.7

Worked following these instructions: http://www.noktec.be/python/how-to-install-pyqt4-on-osx with important exceptions.

1. I installed sip and pyqt against my virtualenv, not against the system python
2. I had to get g++-4.2 to precede g++-4.6 on my path, which was hard.

This command:
PATH=/usr/bin:$PATH CC=g++-4.2 CXX=g++-4.2 ~/virtual-python/bin/python configure.py -d ~/virtual-python/lib/python2.7/site-packages/ --verbose

worked, whereas this one:

CC=g++-4.2 CXX=g++-4.2 ~/virtual-python/bin/python configure.py -d ~/virtual-python/lib/python2.7/site-packages/ --verbose

did not.

Similarly, needed same prefixes when doing make.