Squeak smalltalk dumps with <_pthread_sigmask+0x53e> at /lib/libthr.so.3

Hello,

I compiled the opensmalltalk-vm sources from Git on FreeBSD.
[edwin@ottopedi ~]$ uname -a
FreeBSD ottopedi 12.3-RELEASE-p1 FreeBSD 12.3-RELEASE-p1 GENERIC  amd64

There were no errors during the compilation, but when executing, at various
places, I get core dumps, allways with the following comments:

C stack backtrace & registers:
don't know how to derive register state from a ucontext_t on this platform
*0x0 <???> at ???
0x25c04a <reportStackState+0xda> at
/usr/home/edwin/Smalltalk53/opensmalltalk-vm/building/linux64x64/squeak.cog.spur/build/squeak
0x25e237 <sigsegv+0x137> at
/usr/home/edwin/Smalltalk53/opensmalltalk-vm/building/linux64x64/squeak.cog.spur/build/squeak
0x800414c6e <_pthread_sigmask+0x53e> at /lib/libthr.so.3

I don't know how to look further now. My first idea is that somewhere in
the sources, there is an ifdef FREEBSD missing, just to derive the register
state. As the code looks massive, I would like to asl if someone could
confirm (or not), I am thinking in the right direction.

But as I seem to be the only one with this problem (I read no otther
reports about it on the squeal mailing lists), it might be a local problem
also. Is there a way to find out?

I would appreciate if someone could give some hints. My experience with
FreeBSD is just using and installing, this stuff is alien for me

Kind regards,

Edwin Ancaer
*;