Hi, I am experimenting with swig bindings for guile on Mac OS X. One of the swig tests (the integer test) is failing. I am aware that swig is not guile, but the bug seems to be reproducible in pure guile as well. When I calculate (2^64) -1 on the Mac OS X platform, it returns -1. On my fedora system, the same calculation returns 18446744073709551615 The scheme command used for this is (display (- (expt 2 64) 1))(newline) Note that I don't have direct access to a 64-bit Mac OS X system. I have run into this bug via that travis CI service. Here's a link to one of the test runs for swig on that platform: https://travis-ci.org/gjanssens/swig/jobs/13730706 The output of the calculation as given above is on line 2161. (The test is missing the (newline) part, so some additional output is appended on the same line. This comes from another display command though). I'm not sure what additional information I can provide. If you need, I can run more tests indirectly on the travis platform, but other than that, my options are fairly limited. Geert