Fix kill fail bug (#11635)

* 1. Remove PYTHON_FLAGS from paddle_build.sh in paddlepaddle/paddle:latest-dev

* 1. Add PYTHON_FLAGS back
2. Change SIGKILL to SIGINT and SIGTERM

* 1. Add setup.py.in back

* 1. add pip install open-cv in Dockerfile to avoid libusb_exit hanging up which is caused by the opencv-python package missing

* 1. Add the && \ to line above

* 1. Remove the notice comment

Dockerfile

@@ -76,7 +76,8 @@ RUN easy_install -U pip && \
     pip install sphinx-rtd-theme==0.1.9 recommonmark
 
 RUN pip install pre-commit 'ipython==5.3.0' && \
-    pip install 'ipykernel==4.6.0' 'jupyter==1.0.0'
+    pip install 'ipykernel==4.6.0' 'jupyter==1.0.0' && \
+    pip install opencv-python
 
 #For docstring checker
 RUN pip install pylint pytest astroid isort

python/paddle/fluid/tests/unittests/CMakeLists.txt

@@ -43,8 +43,6 @@ list(REMOVE_ITEM TEST_OPS test_warpctc_op)
 list(REMOVE_ITEM TEST_OPS test_dist_train)
 list(REMOVE_ITEM TEST_OPS test_parallel_executor_crf)
 list(REMOVE_ITEM TEST_OPS test_parallel_executor_fetch_feed)
-# TODO(wuyi): this test hungs on CI, will add it back later
-list(REMOVE_ITEM TEST_OPS test_listen_and_serv_op)
 foreach(TEST_OP ${TEST_OPS})
     py_test_modules(${TEST_OP} MODULES ${TEST_OP})
 endforeach(TEST_OP)
@@ -52,3 +50,4 @@ py_test_modules(test_warpctc_op MODULES test_warpctc_op ENVS FLAGS_warpctc_dir=$
 py_test_modules(test_dist_train MODULES test_dist_train SERIAL)
 py_test_modules(test_parallel_executor_crf MODULES test_parallel_executor_crf SERIAL)
 py_test_modules(test_parallel_executor_fetch_feed MODULES test_parallel_executor_fetch_feed SERIAL)
+set_tests_properties(test_listen_and_serv_op PROPERTIES TIMEOUT 20)

python/paddle/fluid/tests/unittests/test_listen_and_serv_op.py

@@ -94,7 +94,7 @@ class TestListenAndServOp(OpTest):
         self._wait_ps_ready(p1.pid)
 
         # raise SIGTERM to pserver
-        os.kill(p1.pid, signal.SIGKILL)
+        os.kill(p1.pid, signal.SIGINT)
         p1.join()
 
         # run pserver on CPU in async mode
@@ -102,7 +102,7 @@ class TestListenAndServOp(OpTest):
         self._wait_ps_ready(p2.pid)
 
         # raise SIGTERM to pserver
-        os.kill(p2.pid, signal.SIGKILL)
+        os.kill(p2.pid, signal.SIGTERM)
         p2.join()