Show conversion log on exceptions

src/calibre/srv/jobs.py

@@ -45,6 +45,7 @@ class Job(Thread):
         except WorkerError as err:
             import traceback
             self.traceback = err.orig_tb or traceback.format_exc()
+            self.log_path = getattr(err, 'log_path', None)
         else:
             self.result, self.log_path = result['result'], result['stdout_stderr']
         self.done = True

src/calibre/utils/ipc/simple_worker.py

@@ -20,9 +20,10 @@ from calibre.utils.ipc.launch import Worker
 
 class WorkerError(Exception):
 
-    def __init__(self, msg, orig_tb=''):
+    def __init__(self, msg, orig_tb='', log_path=None):
         Exception.__init__(self, msg)
         self.orig_tb = orig_tb
+        self.log_path = log_path
 
 
 class ConnectedWorker(Thread):
@@ -225,6 +226,10 @@ def fork_job(mod_name, func_name, args=(), kwargs={}, timeout=300,  # seconds
         communicate(ans, w, listener, (mod_name, func_name, args, kwargs,
             module_is_source_code), timeout=timeout, heartbeat=heartbeat,
             abort=abort)
+    except WorkerError as e:
+        if not no_output:
+            e.log_path = w.log_path
+        raise
     finally:
         t = Thread(target=w.kill)
         t.daemon=True

src/pyj/book_list/convert_book.pyj

@@ -92,7 +92,7 @@ def show_failure(response):
         if response.traceback:
             log += response.traceback
         if response.log:
-            log += '\n\n' + _('Conversion log')
+            log += '\n\n' + _('Conversion log') + '\n\n'
             log += response.log
         c.appendChild(E.pre(log))