Index: .github/workflows/build.yml
===================================================================
diff -u -r9ccc962011199f0c4c24fac50908d6a1c69f65c1 -ra5f0ea7f6bfb721ce5e61deca530ca67a178301b
--- .github/workflows/build.yml	(.../build.yml)	(revision 9ccc962011199f0c4c24fac50908d6a1c69f65c1)
+++ .github/workflows/build.yml	(.../build.yml)	(revision a5f0ea7f6bfb721ce5e61deca530ca67a178301b)
@@ -33,15 +33,15 @@
             tcltag: trunk
             experimental: [true]
           - os: ubuntu-latest
-            compiler: clang-12
+            compiler: clang-13
             tcltag: trunk
             experimental: [true]
           - os: ubuntu-latest
             compiler: gcc-10
             tcltag: core-8-6-branch
             experimental: [true]
           - os: ubuntu-latest
-            compiler: clang-12
+            compiler: clang-13
             tcltag: core-8-6-branch
             experimental: [true]
           - os: macos-latest