Several people contacted me about Mac OS X 10.2 so I decided to take the plunge and buy it. I managed to track down the problem and you can find an updated version of Poly/ML in http://www.polyml.org/distrib/polyml-macosx.4.1.3.tar.gz . This contains executable and database and will only run on version 10.2 . I'll update the source in due course.

For those who are interested, the problem was that the kernel included with 10.2 calls a signal handler with different parameters from previous versions. Previously it was called with a sigcontext structure containing register information, now the kernel seems to follow Solaris in providing a ucontext structure. Poly/ML needs this information because it uses a variety of signals to deal with things such as writes to database mutables, long-precision arithmetic and garbage-collection traps. Needless to say the change was not documented and the signal man page still refers to sigcontext, indeed it appears not to have changed since 1994. The only way I managed to find out what was going on was to download the Darwin kernel source and look at that. At least the source is available.

The way the change was made means that it would be difficult to provide a binary that would work under 10.2 and also earlier versions of Mac OS X. It's also difficult to provide source that will automatically select the correct version when it's compiled. I'm going to assume that most people will have upgraded to 10.2 and concentrate on that.

Let me know if there are any further problems.

David.