[C++-sig] Boost python in OS X, with non-framework python 2.4

[Lars Yencken]

Hello!

[apologies for long post ahead]

I've been using boost python with some of my research code for a
little while on linux, and have really enjoyed it. I've been having
trouble on my new mac laptop though, since (a) I have a large codebase
that needs python2.4, and (b) I can't seem to compile and link boost
python extensions against python2.4 as provided by fink or darwin
ports.

No matter what I try, I can only get extensions successfully compiled
for the framework python2.3  which comes with OS X. I know this
because with python 2.4 (from fink) my code gives

    Fatal Python error: Interpreter not initialized (version mismatch?)
    Abort trap

whereas this doesn't occur with 2.3, where the extension works fine.
If I use boost.python from fink or darwin ports, the problem is the
same. I've tried installing my own version, using configure arguments
--with-python=/sw/bin/python2.4 --with-python-root=/sw
--with-python-version=2.4 --with-libraries=python. Here's the output
from the previous compilation stage for my extension, which appears to
be successful:

g++ -o dataType.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost dataType.cpp
g++ -o entry.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost entry.cpp
g++ -o alignment.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost alignment.cpp
g++ -o ambiguousAlignment.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost ambiguousAlignment.cpp
g++ -o utils.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost utils.cpp
g++ -o dataType.dylib -dylib -bundle -L/sw/lib -lpython2.4
-lboost_python -lm dataType.o entry.o alignment.o ambiguousAlignment.o
utils.o

I did see some earlier posts on this, but they seemed a bit
unresolved. From my understanding, regardless of command line options
you give to configure, if you compile boost.python using the darwin
toolset, it links against the framework python. I tried building using
the gcc toolset, and specifying --with-python=/sw/bin/python2.4
--with-python-root=/sw --with-python-version=2.4
--with-libraries=python.

If you do this, the g++ arguments are actually wrong for OS X, and you
have to manually perform the final linking step yourself. This works,
if you change

   c++ -s -fPIC -shared -o <target dylib> <long list of object files>

to

   c++ -dynamiclib -dynamic -o <target dylib> <long list of object
files> -L/sw/lib -lpython2.4

for the targets libboost_python-gcc-1_33_1.dylib and
libboost_python-gcc-d-1_33_1.dylib (leaving in the -g flag for the
debug library). I can then install it.

After all this, I try recompiling.

g++ -o dataType.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost dataType.cpp
g++ -o entry.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost entry.cpp
g++ -o alignment.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost alignment.cpp
g++ -o ambiguousAlignment.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost ambiguousAlignment.cpp
g++ -o utils.o -c -Wall -O3 -fPIC -I/sw/include/python2.4
-I/usr/local/include/boost utils.cpp
g++ -o dataType.so -dylib -bundle -L/sw/lib -lpython2.4
-lboost_python-gcc-1_33_1 -lm dataType.o entry.o alignment.o
ambiguousAlignment.o utils.o

Now, when I test, I get same error, but with python2.3, python2.4 and
python2.5. This to me indicates that either my library, or boost's
library, has been compiled with a mixture of python flavours,
acceptable to none. Does anyone have any ideas on what else I could
try, or suggestions in the case I'm barking up the wrong tree?

Many thanks,
Lars