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I could not get Python3 to build on my OSX 10.6.8 box as per the instructions on the website (or those in the README). It "configures" , but does not "make" :
 
<snip>
IOError: $MACOSX_DEPLOYMENT_TARGET mismatch: now "10.4" but "10.5" during configure
make: *** [Include/Python-ast.h] Error 1
</snip>
I can fix this by issuing
export MACOSX_DEPLOYMENT_TARGET=10.6
EXTRA WRINKLE:
It then configures and makes. But if I select a new terminal (i.e. without the exported env variable, and "make clean ; configure ; make" it continues to make perfectly. Not sure what is going on here.
IMPORTANT:
**** To replicate this bug I had to get a fresh mercurial clone ****
Q: Is this the correct setting for the TARGET ?
Q: Does this happen for other OSX users (specifically !=10.6 users) ?
Q: Should this be documented to save grief for other newbie OSX devs ?
Full Stack Dump of error :
gcc -c -fno-strict-aliasing -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I. -I./Include -DPy_BUILD_CORE -o Python/_warnings.o Python/_warnings.c
./Parser/asdl_c.py -h ./Include ./Parser/Python.asdl
Traceback (most recent call last):
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/site.py", line 553, in <module>
 main()
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/site.py", line 535, in main
 known_paths = addusersitepackages(known_paths)
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/site.py", line 268, in addusersitepackages
 user_site = getusersitepackages()
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/site.py", line 243, in getusersitepackages
 user_base = getuserbase() # this will also set USER_BASE
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/site.py", line 233, in getuserbase
 USER_BASE = get_config_var('userbase')
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/sysconfig.py", line 535, in get_config_var
 return get_config_vars().get(name)
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/sysconfig.py", line 434, in get_config_vars
 _init_posix(_CONFIG_VARS)
 File "/Library/Frameworks/Python.framework/Versions/7.0/lib/python2.7/sysconfig.py", line 313, in _init_posix
 raise IOError(msg)
IOError: $MACOSX_DEPLOYMENT_TARGET mismatch: now "10.4" but "10.5" during configure
make: *** [Include/Python-ast.h] Error 1