Use of uninitialized value in concatenation (.) or string RPerl/Compiler.pm line 1503

[hakonhagland]

Hello! I have this simple module:

# [[[ HEADER ]]]
use RPerl;
package MyModule;
use strict;
use warnings;
our $VERSION = 0.001_000;

# [[[ CRITICS ]]]
## no critic qw(ProhibitUselessNoCritic ProhibitMagicNumbers RequireCheckedSyscalls)  # USER DEFAULT 1: allow numeric values & print operator

# [[[ SUBROUTINES ]]]

sub foo {
    { my void $RETURN_TYPE };
    print "MyModule: foo()\n";
    return;
}

1;

If I compile this, I get a warning:

$ rperl MyModule.pm 
Use of uninitialized value in concatenation (.) or string at /home/hakon/perlbrew/perls/5.30.0-reloc/lib/site_perl/5.30.0/RPerl/Compiler.pm line 1503, <$FILE_HANDLE> line 9.