Which nightly version of Rust to use

[Hocuri]

The readme says that mutagen needs a nightly rust version, but after following the instructions from https://lib.rs/crates/mutagen and then running cargo +nightly test, I get a very long error message:

Details

cargo +nightly test
    Updating crates.io index
    Blocking waiting for file lock on package cache
    Blocking waiting for file lock on package cache
    Blocking waiting for file lock on package cache
   Compiling mutagen-plugin v0.1.2
   Compiling deltachat v1.115.0 (/home/jonathan/deltachat-android/jni/deltachat-core-rust)
error[E0557]: feature has been removed
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:1:12
  |
1 | #![feature(plugin_registrar, quote, rustc_private, custom_attribute)]
  |            ^^^^^^^^^^^^^^^^ feature has been removed
  |
  = note: a __rustc_plugin_registrar symbol must now be defined instead

error[E0557]: feature has been removed
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:1:30
  |
1 | #![feature(plugin_registrar, quote, rustc_private, custom_attribute)]
  |                              ^^^^^ feature has been removed

error[E0557]: feature has been removed
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:1:52
  |
1 | #![feature(plugin_registrar, quote, rustc_private, custom_attribute)]
  |                                                    ^^^^^^^^^^^^^^^^ feature has been removed
  |
  = note: removed in favor of `#![register_tool]` and `#![register_attr]`

error[E0557]: feature has been removed
  --> src/lib.rs:30:12
   |
30 | #![feature(custom_attribute)]
   |            ^^^^^^^^^^^^^^^^ feature has been removed
   |
   = note: removed in favor of `#![register_tool]` and `#![register_attr]`

error[E0463]: can't find crate for `rustc_plugin`
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:3:1
  |
3 | extern crate rustc_plugin;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
  |
  = help: maybe you need to install the missing components with: `rustup component add rust-src rustc-dev llvm-tools-preview`

error[E0463]: can't find crate for `syntax`
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:4:1
  |
4 | extern crate syntax;
  | ^^^^^^^^^^^^^^^^^^^^ can't find crate

error[E0463]: can't find crate for `smallvec`
 --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/lib.rs:9:1
  |
9 | extern crate smallvec;
  | ^^^^^^^^^^^^^^^^^^^^^^ can't find crate

error[E0432]: unresolved imports `super::Resizer`, `super::MutatorPlugin`, `super::MutationType`, `super::Mutation`
  --> /home/jonathan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mutagen-plugin-0.1.2/src/bounded_loop.rs:10:5
   |
10 | use super::Resizer;
   |     ^^^^^^^^^^^^^^
   |
  ::: /home/jonathan/deltachat-android/jni/deltachat-core-rust/target/debug/build/mutagen-plugin-a5d018188c651b10/out/plugin_ops.rs:1:5
   |
1  | use super::MutatorPlugin;
   |     ^^^^^^^^^^^^^^^^^^^^
...
5  | use super::{MutationType, Mutation};
   |             ^^^^^^^^^^^^  ^^^^^^^^

error: cannot find macro `quote_expr` in this scope
  --> /home/jonathan/deltachat-android/jni/deltachat-core-rust/target/debug/build/mutagen-plugin-a5d018188c651b10/out/plugin_ops.rs:29:13
   |
29 |             quote_expr!(p.cx(), {
   |             ^^^^^^^^^^

[cut]

error: could not compile `mutagen-plugin` (lib) due to 345 previous errors

Probably I need to use an older nightly - which one?

[samuelpilz]

Yes, some stuff has changed on nightly. I am working on fixes that work on stable, but it will take some more weeks.

[samuelpilz]

Sorry, my previous comment is not correct for your error. The 0.1 published to crates.io is not up-to-date. Using mutagen as described in the readme of this repository should work fine.