$ perl -Mstrict -wcE 'my @x = map my $x = $_, 2; say $x'
-e syntax OK
$ perl -Mstrict -wcE 'my @x = map {my $x = $_} 2; say $x'
Global symbol "$x" requires explicit package name at -e line 1.
-e had compilation errors.

##</code><code>##

$ perl -Mstrict -wE 'my @x = map my $x = $_, 2; say $x'
Use of uninitialized value $x in say at -e line 1.
$ perl -Mstrict -wE 'my $x; my @x = map $x = $_, 2; say $x'
2