[rls::build::cargo] error deleting file

[schomatis]

I'm getting this spurious error frequently in the logs, doesn't seem important but I was wondering if (following 801cef4) it could be demoted to a trace (if not altogether made silent).

rls/rls/src/build/cargo.rs

Line 432 in 9692ca8

debug!("error deleting file, {}: {}", name, e);

It seems that exec (at least in my local setup) takes long enough to have running concurrently the check with and without --test, with the two threads competing to remove the same file.

[schomatis]

I'm also not sure why do we explicitly remove the .json file, it seems the handler just overwrites it in

https://github.com/rust-lang/rust/blob/817d2feb13dd1faad47ec699cd473b8be2093ec9/src/librustc_save_analysis/lib.rs#L1052-L1056

[schomatis]

Closing in favor of #1485.