use strict;
use warnings;
use diagnostics;

##</code><code>##

$ perl -Mstrict -Mwarnings -le 'for (0..1) { our $x = $_ } print $x'
Variable "$x" is not imported at -e line 1.
Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.

##</code><code>##

$ perl -Mstrict -Mwarnings -le 'use diagnostics; for (0..1) { our $x = $_ } print $x'
Variable "$x" is not imported at -e line 1 (#1)
    (W misc) With "use strict" in effect, you referred to a global variable
    that you apparently thought was imported from another module, because
    something else of the same name (usually a subroutine) is exported by
    that module.  It usually means you put the wrong funny character on the
    front of your variable.
    
Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors (#2)
    (F) You've said "use strict" or "use strict vars", which indicates 
    that all variables must either be lexically scoped (using "my" or "state"), 
    declared beforehand using "our", or explicitly qualified to say 
    which package the global variable is in (using "::").
    
Uncaught exception from user code:
	Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.
 at -e line 1.