[WIP] Replace dtolnay/rust-toolchain action with rustup commands

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original prompt

Replace all uses of dtolnay/rust-toolchain action with equivalent rustup shell commands in the CI workflows.

Background

The zizmor branch has been working on pinning actions and addressing security concerns. The dtolnay/rust-toolchain action was intentionally left unpinned because alternatives should be explored first, including manual rustup commands. This PR implements that alternative.

Changes Required

.github/workflows/ci.yml

Replace dtolnay/rust-toolchain in the following jobs:

1. test (line 190) - Ubuntu only

   • Replace uses: dtolnay/rust-toolchain@stable with:

   - name: Install Rust
     run: |
       rustup update stable
       rustup default stable

2. test-journey (line 214) - Ubuntu only

   • Same replacement as test

3. test-fast (line 242) - Multi-platform including Windows

   • Replace with (note shell: bash since this runs on Windows):

   - name: Install Rust
     shell: bash
     run: |
       rustup update stable
       rustup default stable

4. test-fixtures-windows (line 302) - Windows only

   • Replace with (note shell: bash):

   - name: Install Rust
     shell: bash
     run: |
       rustup update stable
       rustup default stable

5. test-32bit-windows-size-doc (lines 413-415) - Windows only

   • Replace uses: dtolnay/rust-toolchain@stable with targets: ${{ env.TARGET }} with:

   - name: Install Rust
     shell: bash
     run: |
       rustup update stable
       rustup default stable
       rustup target add "$TARGET"

   • Note: $TARGET is already defined at job-level env as i686-pc-windows-msvc

6. lint (lines 434-437) - Ubuntu only

   • Replace uses: dtolnay/rust-toolchain@master with toolchain: stable and components: clippy,rustfmt with:

   - name: Install Rust
     run: |
       rustup update stable
       rustup default stable
       rustup component add clippy rustfmt

.github/workflows/release.yml

7. build-release (lines 250-254)

   • Replace uses: dtolnay/rust-toolchain@master with toolchain: ${{ matrix.rust }} and targets: ${{ matrix.target }} with:

   - name: Install Rust
     env:
       RUST: ${{ matrix.rust }}
     run: |
       rustup update "$RUST"
       rustup default "$RUST"
       rustup target add "$TARGET"

   • Note: $TARGET is already defined at job-level env. RUST is defined at step-level because it's only needed in this step.
   • Do NOT specify shell: since the workflow has a default of bash at the workflow level.

8. installation (lines 546-550)

   • Move the step-level env: variables RUST and TARGET from the existing cargo install step (lines 557-559) to the job-level env: block
   • Replace uses: dtolnay/rust-toolchain@master with:

   - name: Install Rust
     run: |
       rustup update "$RUST"
       rustup default "$RUST"
       rustup target add "$TARGET"

   • Update the existing "Installation from crates.io" step to remove its step-level env: block (since RUST and TARGET will now be at job level)
   • Do NOT specify shell: since the workflow has a default of bash at the workflow level.

Important Guidelines

• Do NOT use ${{ }} interpolation inside shell script run: blocks - use environment variables instead
• Only specify shell: bash when necessary (i.e., on Windows jobs in ci.yml where there's no workflow-level default)
• Do NOT specify shell: bash in release.yml jobs since there's already a workflow-level default
• Follow the existing pattern used in the wasm job of ci.yml which already uses manual rustup commands

This pull request was created from Copilot chat.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[EliahKagan]

Although this error has happened before when it shouldn't, I've done a fair bit of testing of Copilot features over a short time very recently and the error message might potentially be accurate. (This review is basically a note to self to check that before reporting a bug.) I'll close this.