Surprised that editors/emacs26 has rust as a dependency

[Christopher Pinon <cjpinon%secondfloor.xyz@localhost>]

Hi,

I'm on NetBSD-8.1 amd64, using an updated pkgsrc stable.

I started to compile editors/emacs26 (emacs26-26.2) last night and saw
that it has rust as a dependency, which surprised me! When I compiled
emacs26-26.1 back in April using pkgsrc-2019Q1, rust wasn't a
dependency.

Last night, I cut the compilation process short because I didn't want to
wait for rust to compile, but I'm wondering: why rust as a dependency?
(I haven't yet tried to look into this.)

Thanks,
C.