Cargo Features for *WASM* environments are sub-optimal. about instant HOT 1 OPEN

Further on this topic, separated into a comment to preserve the purity of the issue OP, here is a link to an external, down-stream issue (rustwasm/wasm-bindgen#2215) which demonstrate that problem number 1 means that users that consume other crates, like parking_lot, in the WASM environment are expected to know about instant's need for either the wasm-bindgen or stdweb features.

I, myself, stumbled upon this while using wgpu which, in turn, uses parking_lot. I later learned that instant is a very useful crate and interesting to me, too (hence item 2 in the OP) but, at the time, I had never heard of it and certainly did not know its usage requirements.

from instant.