The altperl tools use

require '@@PGLIBDIR@@/slon-tools.pm';

and that is set to

-e "s#@@PGLIBDIR@@#$(pglibdir)#;" \

but the module is actually installed at

$(INSTALL_DATA)   slon-tools           $(DESTDIR)$(perlsharedir)/slon-tools.pm

So if these are different, then nothing will work.

The required change is

-                       -e "s#@@PGLIBDIR@@#$(pglibdir)#;" \
+                       -e "s#@@PGLIBDIR@@#$(perlsharedir)#;" \

in tools/altperl/Makefile.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/