Index: .github/workflows/build.yml
===================================================================
diff -u -r96f4eb32ae0c031f6dc95644cfe8360f6871140c -r1b5265205ba0b199463e6d0875d8acd0aa29459e
--- .github/workflows/build.yml	(.../build.yml)	(revision 96f4eb32ae0c031f6dc95644cfe8360f6871140c)
+++ .github/workflows/build.yml	(.../build.yml)	(revision 1b5265205ba0b199463e6d0875d8acd0aa29459e)
@@ -23,10 +23,18 @@
             experimental: [true]
           - os: ubuntu-latest
             compiler: gcc-10
+            tcltag: trunk
+            experimental: [true]
+          - os: ubuntu-latest
+            compiler: clang-12
+            tcltag: trunk
+            experimental: [true]
+          - os: ubuntu-latest
+            compiler: gcc-10
             tcltag: core-8-6-branch
             experimental: [true]
           - os: ubuntu-latest
-            compiler: clang-11
+            compiler: clang-12
             tcltag: core-8-6-branch
             experimental: [true]
           - os: macos-latest