It aborts just after doing a uname call, suspect the 10 (two digits ?),
runs on versions 7 & 8 ok.
Last part of truss output:-
open64("/usr/tcl8.4.6/library/encoding/iso8859-1.enc", O_RDONLY) Err#2 ENOENT
resolvepath("/tcl8.4.6/library/encoding", 0xFFBFE248, 1024) Err#2 ENOENT
access("/tcl8.4.6", F_OK) Err#2 ENOENT
open64("/tcl8.4.6/library/encoding/iso8859-1.enc", O_RDONLY) Err#2 ENOENT
brk(0x00188868) = 0
brk(0x0018A868) = 0
brk(0x0018A868) = 0
brk(0x0018C868) = 0
brk(0x0018C868) = 0
brk(0x0018E868) = 0
uname(0xFFBFEC40) = 1
ioctl(0, TCGETA, 0xFFBFF1BC) = 0
brk(0x0018E868) = 0
brk(0x00190868) = 0
sigaction(SIGABRT, 0x00000000, 0xFFBFE230) = 0
llseek(0, 0, SEEK_CUR) = 10820
sigaction(SIGABRT, 0xFFBFE100, 0xFFBFE180) = 0
sigprocmask(SIG_UNBLOCK, 0xFFBFE1B0, 0x00000000) = 0
getpid() = 10219 [10218]
kill(10219, SIGABRT) = 0
Received signal #6, SIGABRT [default]
siginfo: SIGABRT pid=10219 uid=202

Just tried 8.4.9 binary release, same problem.

Stefan Grubitz reports 8.4.0 work OK under Solaris 10.

I can confirm the crash on a fresh install of Solaris 10. It works with
8.4.1 and crashes with any Tclkit>8.4.2 The ActiveTcl tclkit (8.4.10) works fine
on Solaris 10, so it probably has to do with the way it was compiled, not Tcl
itself?

If I edit genkit85 and add set env(CC) "gcc -static-libgcc" in the SunOS branch
of switch -glob $tcl_platform(os), I am able to compile a tclkit in Solaris 8
that does not crash in Solaris 10. I have tested this to work with both tcl
8.5a2 and 8.5a3

I've just installed ActiveTcl 8.4.11 and indeed the tclkit supplied work
fine under solaris 10.
I copied and rename the ActiceTcl base-tk-solaris-sparc to tclkit.

So the solution is to use the binary tclkits supplied as part of the ActiveTcl
Distro.