From d473183fe9998a8cc8675f8f421fd2ab7044b784 Mon Sep 17 00:00:00 2001
From: Felix Prasanna <fpx@mit.edu>
Date: Fri, 12 Jan 2024 17:14:34 -0500
Subject: [PATCH 1/4] use rustup override set to select toolchain

Using rustup override set will override a local rust-toolchain.toml file
while rustup default will not.
---
 action.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/action.yml b/action.yml
index 45eda54..997b954 100644
--- a/action.yml
+++ b/action.yml
@@ -138,7 +138,7 @@ runs:
             toolchain=stable
           fi
           rustup toolchain install $toolchain${{steps.flags.outputs.targets}}${{steps.flags.outputs.components}} --profile minimal${{steps.flags.outputs.downgrade}} --no-self-update
-          rustup default $toolchain
+          rustup override set $toolchain
         fi
 
     - id: versions

From c6086ae6e539b9cca10fba3642fe77e559ba5705 Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Sat, 13 Jan 2024 15:54:38 +0000
Subject: [PATCH 2/4] test: add toolchain file override test

---
 .github/workflows/ci.yml | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 521e3f6..5fc202d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,8 +12,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        os:
+          - ubuntu-latest
+          - windows-latest
+          - macos-latest
+        write-toolchain-file:
+          - false
+          - true
         rust:
-          # Test with toolchain file override
+          # use stable toolchain as default
           - null
 
           # Test that the sparse registry check works.
@@ -23,21 +30,17 @@ jobs:
           - "nightly"
           - "beta"
           - "stable"
-        os:
-          - ubuntu-latest
-          - windows-latest
-          - macos-latest
     steps:
       - uses: actions/checkout@v4
 
       # Test toolchain file support
       - name: Write rust-toolchain.toml
-        if: matrix.rust == null
+        if: matrix.write-toolchain-file
         shell: bash
         run: |
           cat <<EOF >>rust-toolchain.toml
           [toolchain]
-          channel = "nightly-2024-01-11"
+          channel = "nightly-2024-01-10"
           components = [ "rustfmt", "rustc-dev" ]
           targets = [ "wasm32-unknown-unknown", "thumbv7m-none-eabi" ]
           profile = "minimal"
@@ -59,6 +62,20 @@ jobs:
       - name: Check ${{'${{steps.toolchain.outputs.rustup-version}}'}}
         run: echo '${{steps.toolchain.outputs.rustup-version}}'
 
+      - name: Check lack of toolchain input or file results in stable
+        if: !matrix.write-toolchain-file && matrix.rust == null
+        shell: bash
+        run: |-
+          rustcv="$(rustc --version)"
+          [[ "$rustcv" != *"nightly"* && "$rustcv" != *"beta"* ]]
+
+      - name: Check toolchain file is being overridden
+        if: matrix.write-toolchain-file
+        shell: bash
+        run: |-
+          rustcv="$(rustc --version)"
+          [[ ! ( "$rustcv" == *"nightly"* && "$rustcv" == *"2024-01-10"* ) ]]
+
       - shell: bash
         run: rustc --version && cargo --version
 

From aa089182f268c0255577cdc57a82a9b0819d59c3 Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Sat, 13 Jan 2024 15:57:48 +0000
Subject: [PATCH 3/4] ci: fix conditional

---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5fc202d..c9120aa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -63,7 +63,7 @@ jobs:
         run: echo '${{steps.toolchain.outputs.rustup-version}}'
 
       - name: Check lack of toolchain input or file results in stable
-        if: !matrix.write-toolchain-file && matrix.rust == null
+        if: matrix.write-toolchain-file == false && matrix.rust == null
         shell: bash
         run: |-
           rustcv="$(rustc --version)"

From ba41ca6f71dca3d3a627600631fedb7f260d083e Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Sat, 13 Jan 2024 16:03:46 +0000
Subject: [PATCH 4/4] ci: clearer test names

---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c9120aa..8f3020a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ on:
 
 jobs:
   install:
-    name: Rust ${{matrix.rust || '(toolchain file)'}} ${{matrix.os}}
+    name: Rust ${{matrix.rust || '(default)'}} (toolchain-file=${{matrix.write-toolchain-file}}) (${{matrix.os}})
     runs-on: ${{matrix.os}}
     strategy:
       fail-fast: false