Fails to build latest serde because of out-of-date nightly

[xrl]

I am hitting an issue with serde-derive building on docs.rs: https://docs.rs/crate/rtps/0.2.0/builds/31750

error: the `#[rustc_macro_derive]` attribute is only usable with crates of the `rustc-macro` crate type
 --> .cargo/registry/src/github.1485827954.workers.dev-1ecc6299db9ec823/serde_derive-0.8.11/src/lib.rs:9:3
  |
9 | #[rustc_macro_derive(Serialize)]
  |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The relevant issue in the serde repository: serde-rs/serde#567 .

It looks like the nightly in my build is from September -- perhaps updating it would help?

$ rustc --version
rustc 1.14.0-nightly (289f3a4ca 2016-09-29)

[dtolnay]

Yes updating would help, the rustdoc bug is fixed in rustc 1.14.0-nightly (9c31d76e9 2016-10-03).

[onur]

I updated nightly but still getting same error: https://docs.rs/crate/rtps/0.2.1/builds/31776

[dtolnay]

I cloned rtps 0.2.1 locally and ran cargo doc with rustc 1.14.0-nightly (3210fd5c2 2016-10-05) and it worked. I can try to debug tonight.

[onur]

@dtolnay can you give me rustc command used to compile serde_derive-0.8.11/src/lib.rs from cargo doc --verbose output?

[dtolnay]

rustc /home/david/.cargo/registry/src/github.1485827954.workers.dev-1ecc6299db9ec823/serde_derive-0.8.11/src/lib.rs --crate-name serde_derive --crate-type rustc-macro -C prefer-dynamic -g -C metadata=a27bc5a26505dfc7 -C extra-filename=-a27bc5a26505dfc7 --out-dir rtps/target/debug/deps --emit=dep-info,link -L dependency=rtps/target/debug/deps --extern serde_codegen=rtps/target/debug/deps/libserde_codegen-d813637bf949d9ed.rlib --cap-lints allow

The difference is --crate-type lib vs --crate-type rustc-macro.

You are going to need a new cargo in order to pick up rust-lang/cargo#3064. I am using cargo 0.13.0-nightly (a713da1 2016-10-05).

[onur]

Yes need to start using a newest version of cargo in cratesfyi.

I'll start working on updating cargo.

[xrl]

@onur is there anything I can do to help?

[onur]

I've updated cargo and serde_derive is building fine now.

But for some reason rtps is still failing to build.

I also tried to build rtps on my local machine (rustc 1.14.0-nightly (6dc035ed9 2016-10-15)) and it says:

error: loading custom derive macro crates is experimentally supported (see issue #35900)
  --> src/lib.rs:16:14
   |
16 | #[macro_use] extern crate serde_derive;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add #![feature(proc_macro)] to the crate attributes to enable

error: loading custom derive macro crates is experimentally supported (see issue #35900)
  --> src/lib.rs:16:14
   |
16 | #[macro_use] extern crate serde_derive;
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add #![feature(proc_macro)] to the crate attributes to enable

error: aborting due to 2 previous errors

error: Could not compile `rtps`.

I believe this issue is fixed in docs.rs and rtmp may need an update for #![feature(proc_macro)] definition.

[xrl]

This ticket should be reopened as the problem persists. The rustc version is fine but I think the issue may be an older cargo. Here is a recent travis build of rtps which compiles fine: https://travis-ci.org/xdds/rtps/builds/168725503 (this is the version 0.2.3 I published one day ago).

What version of cargo is the service using?

[onur]

@xrl I updated cargo again and looks like everything is working fine now.

BTW clippy is only working on very latest nightly and docs.rs isn't periodically updating nightly ATM. It's better idea to use clippy as a optional dependency. See #54, #62.

[xrl]

@onur thanks, this is great news! I will take your advice on clippy, it is my highest maintenance dependency.