ken@titan ~/tmp $ cat pm_11137628_pkg_sep_in_string.pl use strict; use warnings; my $user = 'ken'; print "... $user's problem ...\n"; #### ken@titan ~/tmp $ perl -v This is perl 5, version 34, subversion 0 (v5.34.0) built for cygwin-thread-multi ... ken@titan ~/tmp $ perl pm_11137628_pkg_sep_in_string.pl Old package separator used in string at pm_11137628_pkg_sep_in_string.pl line 6. (Did you mean "$user\'s" instead?) Name "user::s" used only once: possible typo at pm_11137628_pkg_sep_in_string.pl line 6. Use of uninitialized value $user::s in concatenation (.) or string at pm_11137628_pkg_sep_in_string.pl line 6. ... problem ... #### $ perlbrew list * perl-5.34.0 perl-5.33.5 perl-5.32.0 perl-5.30.0 #### C:\Users\ken\tmp>perl -v This is perl 5, version 26, subversion 3 (v5.26.3) built for MSWin32-x64-multi-thread ... C:\Users\ken\tmp>perl pm_11137628_pkg_sep_in_string.pl Name "user::s" used only once: possible typo at pm_11137628_pkg_sep_in_string.pl line 6. Use of uninitialized value $user::s in concatenation (.) or string at pm_11137628_pkg_sep_in_string.pl line 6. ... problem ...