gistfile1.txt

.sub 'main'
    $P0 = get_global 'foo'
    set_global 'bar', $P0
    'bar'()
.end

.sub 'foo'
    say "win"
.end

# If you comment this out, it works.
.sub 'bar' :anon
    say "fail"
.end

gistfile2.txt

.sub 'main'
    'bar'()
.end

.sub 'bar' :anon
    say "fail"
.end