fix: properly handle null rollback

lib/workers/repository/process/lookup/index.js

@@ -77,7 +77,16 @@ async function lookupUpdates(config) {
   );
   const updates = [];
   if (!allSatisfyingVersions.length) {
-    updates.push(getRollbackUpdate(config, allVersions));
+    const rollback = getRollbackUpdate(config, allVersions);
+    if (!rollback) {
+      return [
+        {
+          type: 'warning',
+          message: `Can't find version matching ${currentValue} for ${depName}`,
+        },
+      ];
+    }
+    updates.push(rollback);
   }
   const rangeStrategy = getRangeStrategy(config);
   const fromVersion = getFromVersion(config, rangeStrategy, allVersions);

lib/workers/repository/process/lookup/rollback.js

@@ -15,7 +15,7 @@ function getRollbackUpdate(config, versions) {
       { versionScheme },
       'Current version scheme does not support isLessThanRange()'
     );
-    return [];
+    return null;
   }
   const lessThanVersions = versions.filter(version =>
     isLessThanRange(version, currentValue)
@@ -26,7 +26,7 @@ function getRollbackUpdate(config, versions) {
       { packageFile, depName, currentValue },
       'Missing version has nothing to roll back to'
     );
-    return [];
+    return null;
   }
   logger.info(
     { packageFile, depName, currentValue },