Line numbering increment is broken?

[rowet]

$ perl6 -ne 'say "{++$} $_"' /etc/fstab
1
1 #
1 # /etc/fstab
1 # Created by anaconda on Sat Oct 21 20:51:39 2017
1 #
1 # Accessible filesystems, by reference, are maintained under '/dev/disk'
1 # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
1 #25
...