Warn when multiple bundles for a single CLI are found in the toolcache

lib/setup-codeql.js

@@ -356,9 +356,14 @@ async function getCodeQLSource(toolsInput, bypassToolcache, defaultCliVersion, a
                     "toolcache, using that.");
                 codeqlFolder = toolcache.find("CodeQL", candidateVersions[0]);
             }
+            else if (candidateVersions.length === 0) {
+                logger.debug(`Didn't find any versions of the CodeQL tools starting with ${cliVersion} ` +
+                    `in the toolcache. Trying next fallback method.`);
+            }
             else {
-                logger.debug(`Did not find exactly one version of the CodeQL tools starting with ${cliVersion} ` +
-                    `(instead found ${candidateVersions.length}). Trying next fallback method.`);
+                logger.warning(`Found ${candidateVersions.length} versions of the CodeQL tools starting with ` +
+                    `${cliVersion} in the toolcache, but at most one was expected.`);
+                logger.debug("Trying next fallback method.");
             }
         }
     }