How does one debug compat_svr4 binaries that don't fire up?

I need to use Adobe Acrobat Reader for PDF's occasionally, and tried
installing the acroread 4.05 package ... after I fixed the SPARC vs. SPARC64
problems in the Makefile and PLIST (sigh), it installed and then promptly
core dumped.  I have Solaris 7 libraries installed in /emul/svr4/usr/lib.

The entire ktrace is

 28277 ktrace   EMUL  "netbsd"
 28277 ktrace   RET   ktrace 0
 28277 ktrace   CALL  execve(0xffffffffffffd397,0xffffffffffffd1a0,0xffffffffff
ffd1b0)
 28277 ktrace   NAMI  "/usr/pkg/Acrobat4/Reader/sparcsolaris/bin/acroread"
 28277 ktrace   NAMI  "/emul/svr4/usr/lib/ld.so.1"
 28277 ktrace   NAMI  "/emul/svr4"
 28277 ktrace   NAMI  "/emul/svr4/usr/lib/ld.so.1"
 28277 acroread EMUL  "svr4"
 28277 acroread RET   execve JUSTRETURN
 28277 acroread PSIG  SIGBUS SIG_DFL
 28277 acroread NAMI  "acroread.core"

Not much help ... what now?  Do I need Matt's recently-announced emulators
packages (netbsd32_compat14, netbsd32_compat15 and compat14) too?  (I would
think not, I thought compat_svr4 was self-contained - but if I'm running
32-bit Solaris binaries ... erm, I'm confused  (-: )

How do you guys debug problems like this, when there's no ktrace to speak of?

On a different note, I'm seeing encouraging things elsewhere; I had some
problems with vnc, but finally got it to build, which is a step - since it's
a pretty major package in terms of total number of compiled files.  Now if
only the Xvnc server would fire up  :-(  (Oddly, it reads the "fonts.dir" file
in "/usr/lib/X11/fonts/misc/fonts.dir", then proceeds to bitch that it can't
"set default font path" with a perfectly valid font path after it and says
it "count not open default font 'fixed'".  My next head-scratcher ... )

	- Greg