Ask where the preinstalled gcc lives

Author: jcflack

.github/workflows/ci-lazypg.yml

@@ -11,7 +11,7 @@ permissions:
 
 on:
   push:
-    branches: [ master, REL1_6_STABLE ]
+    branches: [ master, REL1_6_STABLE, chore/REL1_6_STABLE/gha ]
   pull_request:
     branches: [ master, REL1_6_STABLE ]
 
@@ -40,6 +40,12 @@ jobs:
 
     steps:
 
+    - name: Run "type gcc" and exit abnormally
+      shell: bash
+      run: |
+        type gcc
+        exit 1
+
     - name: Check for JDK preinstalled
       id: jdkcheck
       shell: bash