When installing zsh on IRIX 5.3 (and maybe other versions of IRIX as
well) the following two problems arise:

It seems that like on SunOS PLIST.shlibs may not be included into PLIST.
This can easily be achived by slightly modifing Makefile.common:

.  if ${OPSYS} == "SunOS" || ${OPSYS} == "IRIX"

The second problem is that in work/zsh-4.2.0/Src/*/Makefile (three files
created dynamically during the build phase; don't know exactly how and
where) INSTALL_PROGRAM (defined here as /usr/local/pkg/bin/install-sh -c
-o root -g sys -m 555) is used to install shared libs (*.$DL_EXT ==
*.so). 
The -s makes install-sh try to strip the *.so file. At least on IRIX 5.3
this results in an error, and consequently each such file does not get
installed unter PREFIX.
Manually deleting the -s before bmaking install works around the
problem. I am not exactly sure where the mistake is, and how it could
best be corrected. 

-- 
Georg Schwarz    http://home.pages.de/~schwarz/
 geos@epost.de     +49 177 8811442