Ta da!

sub sub::source {
    require Sub::Identify;
    my ($class, $func) = @_;
    my $code = $class->can($func) or return;
    return Sub::Identify::stash_name($code);
}

{
    package MyApp;
    use Time::HiRes qw(time);
    use Carp;
}

# Where do MyApp's subs come from?
#
print MyApp->sub::source('carp'), "\n";
print MyApp->sub::source('time'), "\n";

# Where do Carp's subs come from?
#
print Carp->sub::source('carp'), "\n";
print Carp->sub::source('import'), "\n";
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Though it's worth noting that Sub::Name is able to fool Sub::Identify. Also, Moose/Moo/etc do stringy eval stuff that fools Sub::Identify (deliberately).