It's used at build time in 10 crates (9 directly).

Depender (with downloads and own rev deps) grev version
360 1 tetromino build ^0.1.3
230 mail-message build ^0.1.3
130 blazecli build ^0.1.3
120 specto build ^0.1.3
goggled build ^0.1.3
apcacli build ^0.1.3
btrfs-backup build ^0.1.3
notnow build ^0.1.3
chroot-deploy build ^0.1.3