It's used only as a dev dependency in 4 crates.

Depender (with downloads and own rev deps) dwt-systick-monotonic version
4.5K 45 stm32f4xx-hal dev ^1.1
2.8K 1 atsame54_xpro dev ^1.1
epd-spectra dev ^1.1.0
n32g4xx-hal dev ^1.1