ModuleNotFoundError: No module named 'encodings'
jangrewe opened this issue · 8 comments
Description
Mariner can't be started on DietPi
Reproduction Steps
Steps to reproduce the behavior:
- Install DietPi on SD card, boot and do minimal setup to get a running system.
- Follow setup instructions to install mariner package from PPA
- (optional) Install
dbusto make systemd behave properly
Expected Behavior
Mariner starts, preferably from the systemd unit, but manual start via sudo -u mariner mariner is acceptable.
Screenshots / Logs
dietpi@marsbox:~$ sudo -u mariner mariner
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: initfsencoding: Unable to get the locale encoding
ModuleNotFoundError: No module named 'encodings'
Current thread 0xb6fc6a00 (most recent call first):
Aborted
Details:
- Mariner Version: 0.2.0-1
- Printer Model: Elegoo Mars
- Raspberry Pi Model: RPi Zero W
Additional context
Add any other context about the problem here.
I guess this is the problem:
dietpi@marsbox:~$ ls -l /opt/venvs/mariner3d/lib/python3.7/encodings
lrwxrwxrwx 1 root root 28 Apr 17 2021 /opt/venvs/mariner3d/lib/python3.7/encodings -> /usr/lib/python3.7/encodings
But DietPi (based on Rasbian/Debian 11) has Python 3.9, so the correct target for the symlink would be /usr/lib/python3.9/encodings.
Trying the stupid thing and symlinking /usr/lib/python3.7 to /usr/lib/python3.9 helps with a couple of errors, but not enough to get it to work.
I think the big issue is that you're using a packaged venv that makes incorrect assumptions about the environment it gets installed to. Maybe it would be better do do a pip3 install . from sources, when the package gets installed? That would at least ensure the correct environment is used.
I fixed it by copying python 3.9 to the mariner directory, copying some files from python3.7 to python3.9 directory, and editing/relaunching the post-install script. It's faster than compiling required Python on Zero.
Symlink Python 3.7 to the Python 3.9
cd /opt/venvs/mariner3d/bin
sudo ln -s python3.7 /usr/bin/python3.9
Copy Python 3.9 libs to the mariner:
sudo cp -r /usr/lib/python3.9 /opt/venvs/mariner3d/lib/python3.9
Go to the mariner directory and copy some files/dirs from the Python 3.7 to the Python 3.9 directory:
cd /opt/venvs/mariner3d/lib/python3.7
sudo cp no-global-site-packages.txt ../python3.9/no-global-site-packages.txt
sudo cp orig-prefix.txt ../python3.9/orig-prefix.txt
sudo cp site.py ../python3.9/site.py
sudo cp -r site-packages/ ../python3.9/site-packages/
Edit postinstall script adding Python 3.9 version - find the next string and add Python 3.9 version:
sudo nano /var/lib/dpkg/info/mariner3d.postinst
local pythonX_Y=$(cd "$dh_venv_install_dir/lib" && ls -1d python3.9 | tail -n1)
Run postinstall script:
sudo /var/lib/dpkg/info/mariner3d.postinst configure
Now web interface is running but there are another error "Unexpected Printer Response" (I don't have a connected printer yet, so not sure if this error cannot be due to this fact)
Traceback (most recent call last):
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/mariner/server/api.py", line 46, in print_status
selected_file = elegoo_mars.get_selected_file()
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/mariner/mars.py", line 102, in get_selected_file
self._extract_response_with_regex("ok '([^']+)'\r\n", data).group(1)
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/mariner/mars.py", line 39, in _extract_response_with_regex
raise UnexpectedPrinterResponse(data)
mariner.exceptions.UnexpectedPrinterResponse
Thanks @dmpanch, i've now rebuilt everything against Python 3.9 and got it to work, at least theoretically. Your approach is probably a lot faster, so i'll give that a shot for the next time.
But i guess it would be nicer if the package would be built for the current Python version, i guess.
Anyways, now i'm running into a problem similar to yours (which doesn't look like it's python related, though):
The printer returned an unexpected response: 'ok N:20\r\n'
Traceback (most recent call last):
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/flask/app.py", line 1513, in full_dispatch_request
rv = self.dispatch_request()
File "/opt/venvs/mariner3d/lib/python3.9/site-packages/flask/app.py", line 1499, in dispatch_request
return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
File "/opt/mariner/mariner/server/api.py", line 54, in print_status
selected_file = retry(
File "/opt/mariner/mariner/server/utils.py", line 54, in retry
return func()
File "/opt/mariner/mariner/printer.py", line 103, in get_selected_file
self._extract_response_with_regex("ok '([^']+)'\r\n", data).group(1)
File "/opt/mariner/mariner/printer.py", line 40, in _extract_response_with_regex
raise UnexpectedPrinterResponse(data)
mariner.exceptions.UnexpectedPrinterResponse: ok N:20
That looks like mariner doesn't understand what printer's status output?
edit: okay, found this: #180
@jangrewe totally agree with you about the Python version. Btw, today I found PPA with the different Python versions, it would have been useful a few days ago.
Thank you dmpanch, you saved my day.
There is only one slight mistake in your ln command, the parameters need to be swapped; the correct command is
sudo ln -s /usr/bin/python3.9 python3.7
I got around this by starting with a legacy raspbian image. The Debian Buster based image released Dec 2nd 2021 comes with python 3.7 instead of 3.9, and Mariner installs & runs with no issues.
I'm in the process of writing a comprehensive issue with a sane solution included, maybe using pyenv.