#(something like:)
perl -MConfig -e "BEGIN{print 'Perl ', map {$Config{$_},' '}qw/version os archname/ }; use constant X = 1/3;print qq(\n),+X,qq(\n)"

  ----------------------------------------·······
 | Can't modify constant item in scalar assignment at -e line 1, near "3;"
 |  BEGIN not safe after errors--compilation aborted at -e line 1.
 |  Perl 5.14.2  MSWin32-x86-multi-thread
  -----------------------------------------------------------------------·······

  ----------------------------------------·······
 | Can't modify constant item in scalar assignment at -e line 1, near "3;"
 |  BEGIN not safe after errors--compilation aborted at -e line 1.
 |  Perl 5.20.0  MSWin32-x86-multi-thread-64int
  -----------------------------------------------------------------------·······

  ----------------------------------------·······
 | Can't modify constant item in scalar assignment at -e line 1, near "3;"
 |  BEGIN not safe after errors--compilation aborted at -e line 1.
 |  Perl 5.16.2  MSWin32-x64-multi-thread
  -----------------------------------------------------------------------·······