Rollup merge of #37757 - rust-lang:E0002-precision, r=brson
Rollup merge of #37757 - rust-lang:E0002-precision, r=brson

Uncomment some long error explanation

Retry of #37058.

r? @steveklabnik
cc @brson

aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust