Fix CI with the latest Rustup

The latest Rustup does not allow the toolchain specification to be
blank, which we were using.  Fix it by ensuring that only one toolchain
is ever installed in a given task, so we won't need to use the
+$TOOLCHAIN with cargo.

Author: asomers

.cirrus.yml

@@ -8,29 +8,28 @@ env:
   RUSTFLAGS: -D warnings
   RUSTDOCFLAGS: -D warnings
   TOOL: cargo
-  # The MSRV
-  TOOLCHAIN: 1.63.0
+  MSRV: 1.63.0
   ZFLAGS:
 
 # Tests that don't require executing the build binaries
 build: &BUILD
   build_script:
     - . $HOME/.cargo/env || true
-    - $TOOL +$TOOLCHAIN -Vv
-    - rustc +$TOOLCHAIN -Vv
-    - $TOOL +$TOOLCHAIN $BUILD $ZFLAGS --target $TARGET --all-targets
-    - $TOOL +$TOOLCHAIN doc $ZFLAGS --no-deps --target $TARGET
-    - $TOOL +$TOOLCHAIN clippy $ZFLAGS --target $TARGET --all-targets -- -D warnings
+    - $TOOL -Vv
+    - rustc -Vv
+    - $TOOL $BUILD $ZFLAGS --target $TARGET --all-targets
+    - $TOOL doc $ZFLAGS --no-deps --target $TARGET
+    - $TOOL clippy $ZFLAGS --target $TARGET --all-targets -- -D warnings
     - if [ -z "$NOHACK" ]; then mkdir -p $HOME/.cargo/bin; export PATH=$HOME/.cargo/bin:$PATH; fi
     - if [ -z "$NOHACK" ]; then curl -LsSf https://github.com/taiki-e/cargo-hack/releases/latest/download/cargo-hack-${HOST:-$TARGET}.tar.gz | tar xzf - -C ~/.cargo/bin; fi
-    - if [ -z "$NOHACK" ]; then $TOOL +$TOOLCHAIN hack $ZFLAGS check --target $TARGET --each-feature; fi
+    - if [ -z "$NOHACK" ]; then $TOOL hack $ZFLAGS check --target $TARGET --each-feature; fi
 
 # Tests that do require executing the binaries
 test: &TEST
   << : *BUILD
   test_script:
     - . $HOME/.cargo/env || true
-    - $TOOL +$TOOLCHAIN test --target $TARGET
+    - $TOOL test --target $TARGET
 
 # Test FreeBSD in a full VM.  Test the i686 target too, in the
 # same VM.  The binary will be built in 32-bit mode, but will execute on a
@@ -52,10 +51,10 @@ task:
   setup_script:
     - kldload mqueuefs
     - fetch https://sh.rustup.rs -o rustup.sh
-    - sh rustup.sh -y --profile=minimal --default-toolchain $TOOLCHAIN
+    - sh rustup.sh -y --profile=minimal --default-toolchain $MSRV
     - . $HOME/.cargo/env
     - rustup target add i686-unknown-freebsd
-    - rustup component add --toolchain $TOOLCHAIN clippy
+    - rustup component add clippy
   << : *TEST
   i386_test_script:
     - . $HOME/.cargo/env
@@ -76,9 +75,9 @@ task:
     image: ghcr.io/cirruslabs/macos-ventura-base:latest
   setup_script:
     - curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
-    - sh rustup.sh -y --profile=minimal --default-toolchain $TOOLCHAIN
+    - sh rustup.sh -y --profile=minimal --default-toolchain $MSRV
     - . $HOME/.cargo/env
-    - rustup component add --toolchain $TOOLCHAIN clippy
+    - rustup component add clippy
   << : *TEST
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
@@ -129,7 +128,7 @@ task:
   setup_script:
     - mkdir /tmp/home
     - curl --proto '=https' --tlsv1.2 -sSf -o rustup.sh https://sh.rustup.rs
-    - sh rustup.sh -y --profile=minimal --default-toolchain $TOOLCHAIN
+    - sh rustup.sh -y --profile=minimal --default-toolchain $MSRV
     - . $HOME/.cargo/env
     - cargo install cross --version 0.2.1 # cross 0.2.2 bumped the MSRV to 1.58.1
   << : *TEST
@@ -165,9 +164,7 @@ task:
     image: rust:latest
   env:
     TARGET: x86_64-unknown-linux-gnu
-    TOOLCHAIN:
   setup_script:
-    - rustup target add $TARGET
     - rustup component add clippy
   << : *TEST
   before_cache_script: rm -rf $CARGO_HOME/registry/index
@@ -242,37 +239,33 @@ task:
         TARGET: x86_64-unknown-netbsd
   setup_script:
     - rustup target add $TARGET
-    - rustup toolchain install $TOOLCHAIN --profile minimal --target $TARGET
-    - rustup component add --toolchain $TOOLCHAIN clippy
+    - rustup component add clippy
   << : *BUILD
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
 task:
   container:
-    image: rust:1.63.0
+    # Redox's MSRV policy is unclear.  Until they define it, use nightly.
+    image: rustlang/rust:nightly
   env:
     BUILD: check
   name: Redox x86_64
   env:
     HOST: x86_64-unknown-linux-gnu
     TARGET: x86_64-unknown-redox
-    # Redox's MSRV policy is unclear.  Until they define it, use nightly.
-    TOOLCHAIN: nightly
   setup_script:
     - rustup target add $TARGET
-    - rustup toolchain install $TOOLCHAIN --profile minimal --target $TARGET
-    - rustup component add --toolchain $TOOLCHAIN clippy
+    - rustup component add clippy
   << : *BUILD
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
-# Rust Tier 3 targets can't use Rustup
+## Rust Tier 3 targets can't use Rustup
 task:
   container:
     image: rustlang/rust:nightly
   env:
     BUILD: check
     HOST: x86_64-unknown-linux-gnu
-    TOOLCHAIN: nightly
     ZFLAGS: -Zbuild-std
   matrix:
     - name: DragonFly BSD x86_64
@@ -299,7 +292,6 @@ task:
   name: Minver
   env:
     HOST: x86_64-unknown-linux-gnu
-    TOOLCHAIN: nightly
   container:
     image: rustlang/rust:nightly
   setup_script:
@@ -313,5 +305,5 @@ task:
   name: Rust Formatter
   container:
     image: rust:latest
-  setup_script: rustup +$TOOLCHAIN component add rustfmt
-  test_script: $TOOL +$TOOLCHAIN fmt --all -- --check **/*.rs
+  setup_script: rustup component add rustfmt
+  test_script: cargo fmt --all -- --check **/*.rs