warn rather than fail on nightly builds (#1340)

Author: demoray

.github/workflows/build.yml

@@ -36,12 +36,17 @@ jobs:
     runs-on: ubuntu-20.04
     needs:
       - msrv
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
         build:
           - stable
-          - nightly
           - ${{ needs.msrv.outputs.msrv }}
+        experimental:
+          - false
+        include:
+          - build: nightly
+            experimental: true
     steps:
       - uses: actions/checkout@v3
       - uses: Swatinem/rust-cache@v2
@@ -52,12 +57,17 @@ jobs:
     runs-on: ubuntu-20.04
     needs:
       - msrv
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
         build:
           - stable
-          - nightly
           - ${{ needs.msrv.outputs.msrv }}
+        experimental:
+          - false
+        include:
+          - build: nightly
+            experimental: true
     steps:
       - uses: actions/checkout@v3
       - uses: Swatinem/rust-cache@v2
@@ -73,12 +83,17 @@ jobs:
     runs-on: ubuntu-20.04
     needs:
       - msrv
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
         build:
           - stable
-          - nightly
           - ${{ needs.msrv.outputs.msrv }}
+        experimental:
+          - false
+        include:
+          - build: nightly
+            experimental: true
     steps:
       - uses: actions/checkout@v3
       - uses: Swatinem/rust-cache@v2
@@ -92,12 +107,17 @@ jobs:
     runs-on: ubuntu-20.04
     needs:
       - msrv
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
         build:
           - stable
-          - nightly
           - ${{ needs.msrv.outputs.msrv }}
+        experimental:
+          - false
+        include:
+          - build: nightly
+            experimental: true
     steps:
       - uses: actions/checkout@v3
       - uses: Swatinem/rust-cache@v2