From vittore.scolari@gmail.com

The following code works​:

$ perl6 -e 'sub subr() { say "a"; my $c will leave { .say } = 0; }; subr'
a
0

The following doesn't​:

$ cat A.pm6
sub subr() { say "a"; my $c will leave { .say } = 0; }
$ PERL6LIB=. perl6 -e 'use A'
===SORRY!===
Missing serialize REPR function for REPR MVMContext (BOOTContext)