Installs qemu pip requirements from qemu requirements file

ci/docker/qemu/runtime_functions.py

@@ -77,8 +77,8 @@ def run_ut_python3_qemu_internal():
     logging.info("=== NOW Running inside QEMU ===")
     logging.info("PIP Installing %s", pkg)
     check_call(['sudo', 'pip3', 'install', pkg])
-    logging.info("PIP Installing mxnet/tests/requirements.txt")
-    check_call(['sudo', 'pip3', 'install', '-r', 'mxnet/tests/requirements.txt'])
+    logging.info("PIP Installing mxnet/mxnet_requirements.txt") 
+    check_call(['sudo', 'pip3', 'install', '-r', 'mxnet/mxnet_requirements.txt'])
     logging.info("Running tests in mxnet/tests/python/unittest/")
     check_call(['nosetests', '--with-timer', '--with-xunit', '--xunit-file', 'nosetests_unittest.xml', '--verbose', 'mxnet/tests/python/unittest/test_engine.py'])
     # Example to run a single unit test:

ci/docker/qemu/vmcontrol.py

@@ -228,6 +228,7 @@ def qemu_provision(ssh_port=QEMU_SSH_PORT):
         qemu_rsync(ssh_port, x, 'mxnet_dist/')
     qemu_rsync(ssh_port, '/work/runtime_functions.py','')
     qemu_rsync(ssh_port, '/work/vmcontrol.py','')
+    qemu_rsync(ssh_port, 'mxnet/ci/qemu/mxnet_requirements.txt', 'mxnet_requirements.txt')
     qemu_rsync(ssh_port, 'mxnet/tests', 'mxnet')
     logging.info("Provisioning completed successfully.")
 

ci/qemu/README.md

@@ -86,3 +86,7 @@ pip3 install -r mxnet_requirements.txt
 
 
 To access qemu control console from tmux: `ctrl-a a c`
+
+# CI and Testing
+
+Formally, [runtime_functions.py](https://github.com/apache/incubator-mxnet/blob/master/ci/docker/qemu/runtime_functions.py) would [run](https://github.com/apache/incubator-mxnet/blob/8beea18e3d9835f90b59d3f9de8f9945ac819423/ci/docker/qemu/runtime_functions.py#L81) *pip install -r [mxnet/tests/requirements.txt](https://github.com/apache/incubator-mxnet/blob/master/tests/requirements.txt)*. If the requirements change, there can be an unfortunate side-effect that there are no wheel files for Raspberry Pi for the new requirement. This would trigger a build from source on the emulator, which can take a long time and cause job timeouts. Therefore, we no longer install the `tests/requirements.txt` requirements, but rather rely on [mxnet-requirements.txt](https://github.com/apache/incubator-mxnet/blob/master/ci/qemu/mxnet_requirements.txt) to maintain the requirements for the qemu tests. Should any requirements changes lead to a job time out, it is incumbent on the submitter to update the image to include the requirement and unblock ci.