(ironically, macOS's system sed supports the "in-place" options, pkgsrc's macOS configuration apparently feels that it's better to use nbsed instead, *shrug*).
We've had to use pkgsrc sed on macOS since Mountain Lion, as the nativesed is broken with binary files or UTF-8 locales. It would be great if we had a contact at Apple who could fix this, so we no longer need to bootstrap nbsed ;-)
-- Jonathan Perkin - mnx.io - pkgsrc.smartos.org Open Source Complete Cloud www.tritondatacenter.com