rls::actions::hover: extract_decl: error: could not open file

[doxxx]

OS: Windows 10
rls-preview 1.31.6 (6610526 2018-12-01)
rustc 1.31.0 (abe02cefd 2018-12-04)

Using Visual Studio Code, when hovering over unwrap in some code like this:

let i: i32 = "123".parse().unwrap();

The RLS window logs the following errors:

ERROR 2018-12-17T20:57:35Z: rls::actions::hover: extract_decl: error: Io(Some("C:\\Users\\Gordon\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs"), Some("Could not open file: C:\\Users\\Gordon\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs"))
ERROR 2018-12-17T20:57:35Z: rls::actions::hover: failed to extract docs: row: Row(804, PhantomData), file: "C:\\Users\\Gordon\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs" (Io(Some("C:\\Users\\Gordon\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs"), Some("Could not open file: C:\\Users\\Gordon\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs")))

It's looking for a file:

C:\Users\Gordon\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\libcore\result.rs

which is actually located at:

C:\Users\Gordon\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\src\libcore\result.rs

I do still get a tooltip though.

[aloucks]

I'm able to reproduce on stable but not on nightly. The hover mechanism will fall back to using the docs provided by the save-analysis when source extraction fails. That's why you're getting a tooltip, but the docs are limited to a single line.

It looks like the file path coming out of the save-analysis is wrong:

TRACE 2018-12-18T00:30:40Z: rls::actions::hover: tooltip: span_def: Ok(Def { kind: Method, span: Span { file: "C:\\Users\\Aaron\\.rustup\\toolchains\\stable-x86_64-pc-windows-msvc\\lib\\rustlib\\src\\rust\\libcore\\result.rs", range: Range { row_start: Row(804, PhantomData), row_end: Row(804, PhantomData), col_start: Column(11, PhantomData), col_end: Column(17, PhantomData) } }, name: "unwrap", qualname: "core<Result<T, E>>::unwrap", distro_crate: true, parent: None, value: "fn (self) -> T", docs: " Unwraps a result, yielding the content of an [`Ok`]." })

$ find -name result.rs | grep -v tests
./nightly-2018-12-14-x86_64-pc-windows-msvc/lib/rustlib/src/rust/src/libcore/result.rs
./nightly-x86_64-pc-windows-msvc/lib/rustlib/src/rust/src/libcore/result.rs
./stable-x86_64-pc-windows-msvc/lib/rustlib/src/rust/src/libcore/result.rs

[aloucks]

Duplicate of #1171

[doxxx]

Closing in favor of dupe.