"perl -e 'chop foo'" dumps core on "perl, v5.6.1 built for i686-linux", "perl, v5.6.1 built for IP27-irix", and "perl, v5.6.1 built for alpha-dec_osf" (except there it also manages to print an error message "Modification of a read-only value attempted." before it dies horribly). Not on "perl, v5.6.1 built for sun4-solaris", though.

I've compared configs, and I can't find anything distinctively different that would cause sun4-solaris to survive.

perlbug.