Recreate the logs directory on each capture.

src/python/pants/backend/jvm/tasks/jvm_compile/execution_graph.py

@@ -265,6 +265,7 @@ def worker(worker_key, work):
           work()
           result = (worker_key, SUCCESSFUL, None)
         except Exception as e:
+          log.warn(traceback.format_exc())
           result = (worker_key, FAILED, e)
         finished_queue.put(result)
         jobs_in_flight.decrement()

src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py

@@ -434,7 +434,6 @@ def do_compile(self, invalidation_check, compile_contexts):
     for target in invalid_targets:
       cc = compile_contexts[target]
       safe_mkdir(cc.classes_dir)
-      safe_mkdir(cc.log_dir)
 
     # Now create compile jobs for each invalid target one by one, using the classpath
     # generated by upstream JVM tasks and our own prepare_compile().
@@ -520,10 +519,9 @@ def _compile_vts(self, vts, target, sources, analysis_file, upstream_analysis, c
           raise
 
   def _capture_logs(self, workunit, destination):
+    safe_mkdir(destination, clean=True)
     for idx, name, output_name, path in self._find_logs(workunit):
-      dest_path = os.path.join(destination, '{}-{}-{}.log'.format(name, idx, output_name))
-      safe_delete(dest_path)
-      os.link(path, dest_path)
+      os.link(path, os.path.join(destination, '{}-{}-{}.log'.format(name, idx, output_name)))
 
   def _get_plugin_map(self, compiler, options_src, target):
     """Returns a map of plugin to args, for the given compiler.