Pin rust nightly version until ICE is fixed (#1063)

.github/workflows/pull-request.yml

@@ -46,9 +46,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+
+      - name: Set env vars
+        run: |
+          source ci/rust-version.sh
+          echo "RUST_NIGHTLY=$rust_nightly" >> $GITHUB_ENV
+
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: nightly
+          toolchain: ${{ env.RUST_NIGHTLY }}
           override: true
           profile: minimal
           components: clippy

ci/rust-version.sh

@@ -21,18 +21,19 @@ else
   stable_version=1.48.0
 fi
 
-# if [[ -n $RUST_NIGHTLY_VERSION ]]; then
-#   nightly_version="$RUST_NIGHTLY_VERSION"
-# else
-#   nightly_version=2020-08-17
-# fi
+if [[ -n $RUST_NIGHTLY_VERSION ]]; then
+  nightly_version="$RUST_NIGHTLY_VERSION"
+else
+  # nightly 2021-01-13 fails due to https://github.com/rust-lang/rust/issues/80956
+  nightly_version=2021-01-12
+fi
 
 
 export rust_stable="$stable_version"
 export rust_stable_docker_image=solanalabs/rust:"$stable_version"
 
-# export rust_nightly=nightly-"$nightly_version"
-# export rust_nightly_docker_image=solanalabs/rust-nightly:"$nightly_version"
+export rust_nightly=nightly-"$nightly_version"
+export rust_nightly_docker_image=solanalabs/rust-nightly:"$nightly_version"
 
 [[ -z $1 ]] || (