Revert "Will this version of ${foo,, work?"

And check that nothing weird happens on Ubuntu now,
using a preinstalled and a non-preinstalled JDK.

Author: jcflack

.github/workflows/ci-lazypg.yml

@@ -24,19 +24,19 @@ jobs:
     strategy:
       matrix:
         oscc:
-#         - os: ubuntu-latest
-#           cc: gcc
-#         - os: macos-13
-#           cc: clang
-#           pg: 17
+          - os: ubuntu-latest
+            cc: gcc
+          - os: macos-13
+            cc: clang
+            pg: 17
           - os: macos-14
             cc: clang
             pg: 17
 #         - os: windows-latest
 #           cc: msvc
 #         - os: windows-latest
 #           cc: mingw
-        java: [23]
+        java: [21, 23]
 
     steps:
 
@@ -55,7 +55,7 @@ jobs:
           echo >>"$GITHUB_ENV" "JAVA_HOME=${!candidate}"
           echo >>"$GITHUB_OUTPUT" java_found=true
         elif
-          candidate="JAVA_HOME_${JAVAVER}_${RUNNER_ARCH,,}"
+          candidate="JAVA_HOME_${JAVAVER}_$(tr A-Z a-z <<<${RUNNER_ARCH})"
           echo -ne 'no\n'"Environment contains $candidate? "
           [[ -n ${!candidate+set} ]]
         then