$ perl -e' sub say(&@) { "..." } say { "..." };'
$ perl -e'use 5.010; sub say(&@) { "..." } say { "..." };'
syntax error at -e line 1, near "};"
Execution of -e aborted due to compilation errors.
####
$ perl -e' print $x;'
$ perl -e'use 5.012; print $x;'
Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.
##
##
$ perl -e' die "Validation error" if uc(chr(0xE9))=~/\xC9/;'
$ perl -e'use 5.012; die "Validation error" if uc(chr(0xE9))=~/\xC9/;'
Validation error at -e line 1.