[3.9] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (GH-127365) (#127409)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index eb0c11946643498103b1800d18f935241184dc91..ae099ee1dced6e76b9f9b8e8f8626784b1c14ab3 100644 (file)
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -158,7 +158,10 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Install Homebrew dependencies
-      run: brew install pkg-config openssl@3.0 xz gdbm tcl-tk
+      run: |
+        brew install pkg-config openssl@3.0 xz gdbm tcl-tk@8
+        # Because alternate versions are not symlinked into place by default:
+        brew link tcl-tk@8
     - name: Configure CPython
       run: |
         CC=clang \