errorMessage -> errorJson

migrations/schema.sql

@@ -89,7 +89,7 @@ CREATE TABLE IF NOT EXISTS apps(
     tagsJson VARCHAR(2048), // array of tags
     dataDir VARCHAR(256) UNIQUE,
     taskId INTEGER, // current task
-    errorMessage TEXT,
+    errorJson TEXT,
 
     FOREIGN KEY(taskId) REFERENCES tasks(id),
     PRIMARY KEY(id));