spin_on is used at run time in 3 crates (2 directly). It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps) spin_on version
282K 119 futures-lite dev ^0.1.0
sixtyfps-build ^0.1
3 sixtyfps-compilerlib dev ^0.1
1 sixtyfps-macros ^0.1