Using both rust-toolchain and toolchain leads to missing component

[l4l]

Description

Using both toolchain parameter and rust-toolchain file leads to weird behavior. Particularly the error is missing rustfmt: error: 'cargo-fmt' is not installed for the toolchain.

I did 2 pipeline runs, first one without rust-toolchain file (but with parameter toolchain) passes "Check format" step (though fails later, but unrelated to the project) and the second one (with both toolchain parameter and rust-toolchain file) fails with error message error: 'cargo-fmt' is not installed for the toolchain. Diff clearly states that the only interesting change is a rust-toolchain addition.

Workflow code

is the same for both cases:

name: CI

on:
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]

env:
  CARGO_TERM_COLOR: always

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2
    - uses: actions-rs/toolchain@v1
      with:
        toolchain: stable
        components: rustfmt, clippy
    - name: Build
      run: cargo build --verbose
    - name: Check format
      run: cargo fmt -- --check
    - name: Lint
      run: cargo clippy -- -D warnings
    - name: Run tests
      run: cargo test --verbose

Action output

[First] install step

/usr/share/rust/.cargo/bin/rustup show
Default host: x86_64-unknown-linux-gnu
rustup home:  /home/runner/.rustup

info: syncing channel updates for '1.48.0-x86_64-unknown-linux-gnu'
info: latest update on 2020-11-19, rust version 1.48.0 (7eac88abb 2020-11-16)
info: downloading component 'cargo'
info: downloading component 'rust-std'
info: downloading component 'rustc'
info: installing component 'cargo'
info: using up to 500.0 MiB of RAM to unpack components
info: installing component 'rust-std'
info: installing component 'rustc'
1.48.0-x86_64-unknown-linux-gnu (overridden by '/home/runner/work/yofi/yofi/rust-toolchain')
rustc 1.48.0 (7eac88abb 2020-11-16)
/usr/share/rust/.cargo/bin/rustup -V
rustup 1.23.0 (00924c9ba 2020-11-27)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.48.0 (7eac88abb 2020-11-16)`
Installed rustup 1.23.0 support components
/usr/share/rust/.cargo/bin/rustup toolchain install stable --component rustfmt --component clippy
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: latest update on 2020-11-19, rust version 1.48.0 (7eac88abb 2020-11-16)
info: component 'clippy' for target 'x86_64-unknown-linux-gnu' is up to date
info: component 'rustfmt' for target 'x86_64-unknown-linux-gnu' is up to date

  stable-x86_64-unknown-linux-gnu unchanged - rustc 1.48.0 (7eac88abb 2020-11-16)

info: checking for self-updates
info: downloading self-update
Gathering installed versions
  /usr/share/rust/.cargo/bin/rustc -V
  rustc 1.48.0 (7eac88abb 2020-11-16)
  /usr/share/rust/.cargo/bin/cargo -V
  cargo 1.48.0 (65cbdd2dc 2020-10-14)
  /usr/share/rust/.cargo/bin/rustup -V
  rustup 1.23.1 (3df2264a9 2020-11-30)
  info: This is the version for the rustup toolchain manager, not the rustc compiler.
  info: The currently active `rustc` version is `rustc 1.48.0 (7eac88abb 2020-11-16)`

[First] check format step (failed)

error: 'cargo-fmt' is not installed for the toolchain '1.48.0-x86_64-unknown-linux-gnu'
To install, run `rustup component add rustfmt --toolchain 1.48.0-x86_64-unknown-linux-gnu`
Error: Process completed with exit code 1.

[Second] install step

/usr/share/rust/.cargo/bin/rustup show
Default host: x86_64-unknown-linux-gnu
rustup home:  /home/runner/.rustup

stable-x86_64-unknown-linux-gnu (default)
rustc 1.48.0 (7eac88abb 2020-11-16)
/usr/share/rust/.cargo/bin/rustup -V
rustup 1.23.0 (00924c9ba 2020-11-27)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.48.0 (7eac88abb 2020-11-16)`
Installed rustup 1.23.0 support components
/usr/share/rust/.cargo/bin/rustup toolchain install stable --component rustfmt --component clippy
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: latest update on 2020-11-19, rust version 1.48.0 (7eac88abb 2020-11-16)
info: component 'clippy' for target 'x86_64-unknown-linux-gnu' is up to date
info: component 'rustfmt' for target 'x86_64-unknown-linux-gnu' is up to date

  stable-x86_64-unknown-linux-gnu unchanged - rustc 1.48.0 (7eac88abb 2020-11-16)

info: checking for self-updates
info: downloading self-update
Gathering installed versions
  /usr/share/rust/.cargo/bin/rustc -V
  rustc 1.48.0 (7eac88abb 2020-11-16)
  /usr/share/rust/.cargo/bin/cargo -V
  cargo 1.48.0 (65cbdd2dc 2020-10-14)
  /usr/share/rust/.cargo/bin/rustup -V
  rustup 1.23.1 (3df2264a9 2020-11-30)
  info: This is the version for the rustup toolchain manager, not the rustc compiler.
  info: The currently active `rustc` version is `rustc 1.48.0 (7eac88abb 2020-11-16)`

[Second] check format step (succeeded)

Run cargo fmt -- --check

Install step diff

5,14c5
< info: syncing channel updates for '1.48.0-x86_64-unknown-linux-gnu'
< info: latest update on 2020-11-19, rust version 1.48.0 (7eac88abb 2020-11-16)
< info: downloading component 'cargo'
< info: downloading component 'rust-std'
< info: downloading component 'rustc'
< info: installing component 'cargo'
< info: using up to 500.0 MiB of RAM to unpack components
< info: installing component 'rust-std'
< info: installing component 'rustc'
< 1.48.0-x86_64-unknown-linux-gnu (overridden by '/home/runner/work/yofi/yofi/rust-toolchain')
---
> stable-x86_64-unknown-linux-gnu (default)

Expected behavior

Don't really know actually. Perhaps cargo fmt should not fail, or maybe there should be some more descriptive error that toolchain and rust-toolchain are mutually exclusive.

[humb1t]

@l4l thank you - I was trying to understand what's wrong with CI and your hint saved me a lot of time.