Import json_internal

[Xanewok]

Fixing error from rust-lang/rust#53610 (comment), specifically https://ci.appveyor.com/project/rust-lang/rust/build/1.0.8732/job/1vio56we88sawdcb#L11560.

error: cannot find macro `json_internal!` in this scope
   --> tools\rls\src\actions\mod.rs:506:9
    |
506 | /         json!({
507 | |             "watchers": watchers
508 | |         })
    | |__________^
    |
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

Confirmed the error and the fix while using rust-lang/rust@61b0072.

[Xanewok]

Here's a log with -Z external-macro-backtrace in local Rust repo:

C:\Users\Xanewok\Documents\rust>cargo rustc --target x86_64-pc-windows-msvc -j 12 --manifest-path C:\\Users\\Xanewok\\Documents\\rust\\src/tools/rls\\Cargo.toml --features clippy -- -Z external-macro-backtrace
   Compiling rls v0.130.5 (file:///C:/Users/Xanewok/Documents/rust/src/tools/rls)
error: cannot find macro `json_internal!` in this scope
   --> <json macros>:1:30
    |
1   |   ( $ ( $ json : tt ) + ) => { json_internal ! ( $ ( $ json ) + ) } ;
    |   -----------------------------^^^^^^^^^^^^^------------------------- in this expansion of `json!`
    |
   ::: tools\rls\src\actions\mod.rs:506:9
    |
506 | /         json!({
507 | |             "watchers": watchers
508 | |         })
    | |__________- in this macro invocation

(mod.rs:506)

@dtolnay do you have any idea on why it pops only on Windows?

[dtolnay]

I don't know why this would happen on Windows only. Is the Windows build using the most recent version of serde_json and the most recent nightly compiler?

As the name suggests, json_internal is not a public API so be aware that we will break your code if you refer to it. I would recommend finding a different fix.

[nrc]

This seems like a naming/hygiene issue in Rust 2018. Could you file an issue, if there isn't one already please? It does seem really bad to need to use json_internal. If it's the only workaround, could you add a comment that it should be removed.

[Xanewok]

@dtolnay we're using serde_json 1.0.24 but it seems that serde-rs/json@e40cbad is in 1.0.25 - I'll update serde_json then and see if we won't have to pull in json_internal.

EDIT: False alert, didn't notice that python x.py build updated RLS submodule when building against current Rust master; it seems we're using serde_json 1.0.26 and that's the newest.

[Xanewok]

Not required as of rust-lang/rust#53701, turns out that updating serde_json in Rust repo seemed to have fixed the problem.

Cargo workspaces are surely convenient but sometimes it's really not obvious you're still affected by the parent dir/Cargo.toml - it took me some time to realize that the RLS submodule Cargo.lock (with serde_json 1.0.26) is not respected in favour of the Rust CI lockfile (with 1.0.24) 😢

Closing this.