I would like to help get this compiling too. I have run into these issues stated but do not know how to fix them. Can some update the status on this? Also detailed build instructions as well as patches would be appreciated, thanks.

I've added:

#ifdef __sun
  #ifdef __i386
    #include <sys/siginfo.h>
    #include <sys/ucontext.h>
  #endif
#endif

#ifdef __sparc
...

In uxtrap.h and compilation continues, but I get too many undefined symbols:

cc -lsocket -lnsl -o scheme  artutl.o avltree.o bkpt.o bignum.o bigprm.o bitstr.o boot.o char.o daemon.o debug.o dfloat.o error.o extern.o fasdump.o fasl.o fasload.o fixnum.o flonum.o gcloop.o generic.o hooks.o hunk.o intern.o interp.o intprm.o list.o lookprm.o lookup.o memmag.o missing.o obstack.o option.o osscheme.o ostty.o outf.o prim.o primutl.o ptrvec.o purify.o purutl.o regex.o rgxprim.o step.o storage.o string.o syntax.o sysprim.o term.o transact.o tterm.o utils.o vector.o wind.o prosenv.o prosfile.o prosfs.o prosio.o prosproc.o prospty.o prosterm.o prostty.o pruxsock.o intext.o pruxenv.o pruxfs.o pruxio.o ux.o uxctty.o uxenv.o uxfile.o uxfs.o uxio.o uxproc.o uxsig.o uxsock.o uxterm.o uxtop.o uxtrap.o uxtty.o uxutil.o cmpauxmd.o terminfo.o pruxdld.o x11base.o x11term.o x11graph.o x11color.o cmpint.o cmpintmd.o comutl.o usrdef.o   -lcurses  -lm  -lX11
Undefined first referenced
 symbol      in file
asm_nofp_remainder                  cmpintmd.o
asm_generic_positive                cmpintmd.o
_Free                               cmpauxmd.o
asm_nofp_equal                      cmpintmd.o
asm_generic_decrement               cmpintmd.o
asm_generic_increment               cmpintmd.o
interface_to_scheme                 cmpint.o
ia32_cpuid_needed                   fasload.o


I'd appreciate some more guidelines on how to proceed with the build.

cc -DHAVE_CONFIG_H -DMIT_SCHEME -DDEFAULT_LIBRARY_PATH=\"/SPACE/SOFTWARE/SCHEME/mit-2090107/lib/mit-scheme\" -I. -I. -g -o pruxenv.o -c pruxenv.c
"uxtrap.h", line 733: syntax error before or at: *
"uxtrap.h", line 736: syntax error before or at: ucontext_t
"uxtrap.h", line 736: warning: undefined or missing type for: ucontext_t
cc: acomp failed for pruxenv.c
make: * [pruxenv.o] Error 2

Maybe an additional check is needed in configure.in?

I can test compilation on OpenSolaris 8/11 with Sun Studio compiler. Let me know how I can be of help.