# How to install QuantLib with Python SWIG for the first time?

Have just installed Quantlib on Mac

now trying SWIG for Python but get below error

g++ -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -Wl,-F. build/temp.macosx-10.11-intel-2.7/QuantLib/quantlib_wrap.o -L/opt/local/lib -L/opt/local/lib -lQuantLib -o build/lib.macosx-10.11-intel-2.7/QuantLib/_QuantLib.so
ld: warning: ignoring file /opt/local/lib/libQuantLib.dylib, file was built for x86_64 which is not the architecture being linked (i386): /opt/local/lib/libQuantLib.dylib


what am i missing?

• Is this an error or just a warning? Did the compiler create the Python module, and have you tried using it? Jul 31 '16 at 16:25
• yes.. the make -C Python check fails with the following error
– M M
Aug 1 '16 at 21:30

The message is very clear; you are trying to link the wrong architecture.

/opt/local/lib/libQuantLib.dylib you installed was compiled for the x86_64 architecture, but you're trying to link with i386.

i386 is 32 bits and x86_64 is 64 bits, they can't be used together. You should compile SWIG with x86_64, unless you have a 32 bits (very old) machine.

• i didn't give any instruction differently my configure for QuantLib and QuantLib-SWIG... then where is it picking up this difference. i'm on a mac pro with OS X El Captain. what environment variable have i not set or have i incorrectly set for SWIG to think that i'm not in a x86_64 env!!!
– M M
Aug 1 '16 at 21:27

problem was with python

sudo port select --set python python27

;

sudo port select --set python2 python27

fixed the architecture to the right one x86_64 in the build and i stopped getting the linking error.