Mujoco-py: Issues with lock file

Created on 26 Jun 2019 · 9Comments · Source: openai/mujoco-py

Describe the bug
When a mujoco-py program is killed while inside the with LockFile(lockpath) in https://github.com/openai/mujoco-py/blob/d98011924f25466ea5c3819e0460ff8de90e24a2/mujoco_py/builder.py#L89
the next run of mujoco-py hangs indefinitely.

Currently, builder doesn't give any warning about the lock file being waited forever. I think the lock acquisition should have a timeout or at the very least a warning message to describe how to remove the stale lock file.

To Reproduce

Run python program that imports mujoco-py
Kill the process when it's inside the with LockFile block
Run python program that imports mujoco-py
Wait forever

Expected behavior
Either better cleaning of lock file to avoid situtations where stale lock files are left behind or better warning messages.

As a side note, it seems like the lockfile package is deprecated.

Source

hartikainen

👍8

Most helpful comment

It appears lockfile is stored in

your-virtualenv/lib/python3.7/site-packages/mujoco_py/generated/mujocopy-buildlock.lock

Deleting it manually seems to do the trick.

samuela on 25 Sep 2019

👍11

All 9 comments

I think there is a PR in progress that tries to solve this problem, but I don't know what's the status of that is. It's definitely a problem we are aware of.

MillionIntegrals on 8 Jul 2019

Ah, thanks @MillionIntegrals, I totally missed the PR. Would love to see that getting merged soon. I left a couple of minor comments in the PR, hopefully those were useful.

hartikainen on 9 Jul 2019

Just ran into this exact same deadlock. Any known workarounds?

samuela on 25 Sep 2019

It appears lockfile is stored in

your-virtualenv/lib/python3.7/site-packages/mujoco_py/generated/mujocopy-buildlock.lock

Deleting it manually seems to do the trick.

samuela on 25 Sep 2019

👍11

For me, deleting the buildlock file manually did not solve the problem. Now there is no buildlock file anymore (searching linux root for "buildlock" doesn't produce any results), but the error is the same.

I was able to import the mujoco_py and run the few interactive lines from the README.md. Then, I quitted that python session and I was not able to run any mujoco-py programs anymore. The error is raised when the mujoco_py module is imported:

... File "/usr/local/lib/python3.5/dist-packages/fasteners-0.15-py3.5.egg/fasteners/process_lock.py", line 156, in acquire
self._do_open()
File "/usr/local/lib/python3.5/dist-packages/fasteners-0.15-py3.5.egg/fasteners/process_lock.py", line 128, in _do_open
self.lockfile = open(self.path, 'a')
PermissionError: [Errno 13] Permission denied: b'/usr/local/lib/python3.5/dist-packages/mujoco_py-2.0.2.7-py3.5.egg/mujoco_py/generated/mujocopy-buildlock'

I suspect that it may be related to installing the package from source instead of using _pip_. I ran the following under _mujoco-py/_ to install:
sudo python3 setup.py install

Uninstalling by pip and installing from source again did not solve the problem either. It can now import mujoco_py in the interactive python, but can't run the example file (setting_state.py).

System: Ubuntu 16.04, Python 3.5.2, mujoco200, mujoco-py current master branch.

gokhansolak on 25 Oct 2019

Installing the package with pip3 instead of building the repo solved the issue.

gokhansolak on 25 Oct 2019

Is there any progess on this yet? I installed mine with pip3 and I can't even find the "mujocopy-buildlock" in the generated folder. I'm using python version 3.7.5.