Thank you, I narrowed it down from there and got a properly working build. I gather the problem is that in Xcode 4.2 the default compiler was changed to clang, but the version of clang bundled with it has a bug that breaks overflows in intobject.c.
In case anyone else hits this, I fixed this in MacPorts by forcing it to use gcc. Edit the portfile (port edit python27) and add this anywhere after the 5th or so line: configure.compiler llvm-gcc-4 -Derek On Wed, Nov 2, 2011 at 7:41 PM, Guido van Rossum <gu...@python.org> wrote: > Apparently Macports is still using a buggy compiler. I reported a > similar issue before and got this reply from Ned Delly: > > """ > Thanks for the pointer. That looks like a duplicate of Issue11149 (and > Issue12701). Another manifestation of this was reported in Issue13061 > which also originated from MacPorts. I'll remind them that the > configure change is likely needed for all Pythons. It's still safest to > stick with good old gcc-4.2 on OS X at the moment. > """ > > (Those issues are on bugs.python.org.) > > --Guido > > On Wed, Nov 2, 2011 at 7:32 PM, Derek Shockey <derek.shoc...@gmail.com> wrote: >> I just found an unexpected behavior and I'm wondering if it is a bug. >> In my 2.7.2 interpreter on OS X, built and installed via MacPorts, it >> appears that integers are not correctly overflowing into longs and >> instead are yielding bizarre results. I can only reproduce this when >> using the exponent operator with two ints (declaring either operand >> explicitly as long prevents the behavior). >> >>>>> 2**100 >> 0 >>>>> 2**100L >> 1267650600228229401496703205376L >> >>>>> 20**20 >> -2101438300051996672 >>>>> 20L**20 >> 104857600000000000000000000L >> >>>>> 10**20 >> 7766279631452241920 >>>>> 10L**20L >> 100000000000000000000L >> >> To confirm I'm not crazy, I tried in the 2.7.1 and 2.6.7 installations >> included in OS X 10.7, and also a 2.7.2+ (not sure what the + is) on >> an Ubuntu machine and didn't see this behavior. This looks like some >> kind of truncation error, but I don't know much about the internals of >> Python and have no idea what's going on. I assume since it's only in >> my MacPorts installation, it must be build configuration issue that is >> specific to OS X, perhaps only 10.7, or MacPorts. >> >> Am I doing something wrong, and is there a way to fix it before I >> compile? I could find any references to this problem as a known issue. >> >> Thanks, >> Derek >> _______________________________________________ >> Python-Dev mailing list >> Python-Dev@python.org >> http://mail.python.org/mailman/listinfo/python-dev >> Unsubscribe: >> http://mail.python.org/mailman/options/python-dev/guido%40python.org >> > > > > -- > --Guido van Rossum (python.org/~guido) > _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
