[gtkmm] Problem with pkg-config files

[RMM <morelli cs utah edu>]

I ran into a problem with the pkg-config files for gtkmm (i.e.
gtkmm-2.0.pc) and for a number of other other related libraries 
under Windows.  Namely,  the prefix variable is set improperly
as /target.  According to the documentation for pkg-config,
prefix should be set under Windows to the grandparent of the directory
in which the .pc file is located,  provided the last part of the
path is \lib\pkgconfig.  However,  for whatever reason,  that
doesn't seem to be happening for me.  I've tried both the cygwin
port of pkg-config and the native port by Tor Lillqvist,  but
in both cases the result of,  say, 
pkg-config gtkmm-2.0 --cflags
contains flags like -I/target/...

Another irritating problem is that pkg-config seems to ignore
directories in the PKG_CONFIG_PATH variable that contain spaces.
That excludes a lot of files whose default location is under
C:\Program Files\

Of course,  I can probably just move the .pc files somewhere else and
edit them to manually change the prefix to something that works,  but
obviously that's not how things should work.

Anyone know what's going on?

Thanks