Weird bug in Higher Rank Trait Bounds resolutions

[hhirtz]

Stumbled on a weird compilation error triggered by sprs "presence" (??).

The following project fails to build unless extern crate sprs is commented: https://github.com/hhirtz/sprs-hrtb-bug/blob/master/src/lib.rs

Of course the compilation error does not come from this line: it will appear if sprs is used elsewhere in the cargo project. (e.g. you can replace "extern crate" with type Hi = sprs::CsMatView<'static, u32>; to trigger the error).

Happens on
cargo 1.55.0 (32da73ab1 2021-08-23) with sprs 0.11.0 and sprs 0.10.0
cargo 1.49.0 (d00d64df9 2020-12-05) with sprs 0.11.0
cargo 1.42.0 (86334295e 2020-01-31) with sprs 0.10.0

[hhirtz]

sprs 0.9.0 works fine

[hhirtz]

d2f0da7 is the first bad commit

[hhirtz]

Might be related to rust-lang/rust#85063