OK, I figured out the problem with environ. It had been (erroneously) defined before, and now was (properly) un-defined, plus it was not supposed to be accessed anymore. So add in another #ifdef USE_ENVIRON_ARRAY arround the little code in util.c, and then we are set.
Although, I had to throw in a completely empty Perl_my_setenv function. At some point, it should do something, but for now it won't. I am pretty sure current MacPerl does not populate environ, either, so
After a bunch of little things (and forgetting, then remembering, that xsubpp had not been patched and was therefore severely busted for my bleadperl build), I got a little MPW tool for perl.68K, v5.7.0. What does this mean? It means that we are close enough that v5.6.1 should be entirely doable (once the patches are integrated).
I am going to submit a few more patches for bleadperl, then I am going to return to the some other problems (InstallBLIB, maybe Config some more), and hopefully by then v5.6.1 will be ready for me to look at.
I might do some more work tonight (on the aforementioned patches), but not much work the rest of the week after that. Tomorrow is Valentine's Day, and then my three-day MacPerl Work Week is done.