It's used at build time in 11 crates (10 directly).

Depender (with downloads and own rev deps) grev version
1.1K notnow build ^0.1.3
700 apcacli build ^0.1.3
600 blazecli build ^0.1.3
360 1 tetromino build ^0.1.3
230 mail-message build ^0.1.3
210 npd build ^0.1.3
chroot-deploy build ^0.1.3
goggled build ^0.1.3
specto build ^0.1.3
btrfs-backup build ^0.1.3