problem building lang/python25 on Darwin

[Taylor R Campbell <campbell%mumble.net@localhost>]

I'm using pkgsrc-2009Q4 as of a few hours ago, which I just installed
on Mac OS X 10.5.  Building lang/python25 fails file-check, because
lib/python2.5/lib-dynload/pyexpat.so doesn't get built, in turn
because:

...
building 'pyexpat' extension
gcc -fno-strict-aliasing -no-cpp-precomp -fno-common -DNDEBUG -pipe -O2 
-I/usr/include -I/Users/riastradh/pkgsrc/2009Q4/pkg/include 
-DHAVE_EXPAT_CONFIG_H=1 -DUSE_PYEXPAT_CAPI 
-I/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/./Modules/expat
 -I. 
-I/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/./Include 
-I/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/./Mac/Include 
-I. -IInclude -I./Include -I/usr/include 
-I/Users/riastradh/pkgsrc/2009Q4/pkg/include 
-I/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Include 
-I/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4 -c 
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c
 -o 
build/temp.macosx-10.3-i386-2.5/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.o
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:14:26:
 error: expat_config.h: No such file or directory
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:44:1:
 warning: "XmlInitEncodingNS" redefined
In file included from 
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/expat_external.h:12,
                 from 
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/expat.h:18,
                 from 
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:21:
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/pyexpatns.h:64:1:
 warning: this is the location of the previous definition
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:45:1:
 warning: "XmlInitUnknownEncodingNS" redefined
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/pyexpatns.h:66:1:
 warning: this is the location of the previous definition
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:48:1:
 warning: "XmlParseXmlDeclNS" redefined
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/pyexpatns.h:78:1:
 warning: this is the location of the previous definition
/private/tmp/pkgsrc-2009Q4-work/lang/python25/work/Python-2.5.4/Modules/expat/xmlparse.c:77:2:
 error: #error memmove does not exist on this platform, nor is a substitute 
available
...