Windows: Import error after pip install

[Tilix4]

Bug Report

-- edit: removed the checkboxes so that GitHub is no longer confused about open tasks --

• Incorrect functionality

Describe the bug here. If it is a build issue, please note whether the issue was encountered via cmake, pip, or tox.

To Reproduce

1. Operating System: Windows 10
2. Python 3.7.9, CMake installed
3. Example snippet that demonstrates the issue:

ImportError: DLL load failed: The specified module could not be found.

4. OpenTimelineIO 0.13.0

Expected Behavior

The import statement to work correctly.

Logs

Traceback (most recent call last):
  File "C:\Users\User\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "C:\Users\User\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "c:\Users\User\.vscode\extensions\ms-python.python-2020.9.114305\pythonFiles\lib\python\debugpy\__main__.py", line 45, in <module>
    cli.main()
  File "c:\Users\User\.vscode\extensions\ms-python.python-2020.9.114305\pythonFiles\lib\python\debugpy/..\debugpy\server\cli.py", line 430, in main
    run()
  File "c:\Users\User\.vscode\extensions\ms-python.python-2020.9.114305\pythonFiles\lib\python\debugpy/..\debugpy\server\cli.py", line 267, in run_file
    runpy.run_path(options.target, run_name=compat.force_str("__main__"))
  File "C:\Users\User\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "C:\Users\User\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Users\User\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "E:\Logiciels\Stax\Dev\stax\test_otio.py", line 4, in <module>
    import opentimelineio as otio
  File "e:\Logiciels\Stax\Dev\stax\.venv\lib\site-packages\opentimelineio\__init__.py", line 35, in <module>
    from . import (
  File "e:\Logiciels\Stax\Dev\stax\.venv\lib\site-packages\opentimelineio\opentime.py", line 1, in <module>
    from . _opentime import ( # noqa
ImportError: DLL load failed: The specified module could not be found.

[apetrynet]

Hi @Tilix4 !
I suspect this is an issue that's popped up once in awhile. Have you tried the workaround mentioned in this issue? #770 (comment)

[Tilix4]

Hi @apetrynet I've read this thread, but I cannot find site-packages\opentimelineio\cxx-libs, this directory doesn't exist. I did search for .dll but I didn't find any.

I'm installing with pip's --target option.

[apetrynet]

Hmm. OK, good you checked the other issues.
I don't have enough experience with OTIO on windows or usage of the --target option so I'll pass this on to @reinecke and @meshula. Could any of you shed some light on this?

[meshula]

What command line did you use to do the pip install? I notice that you used --target, but it's hard to guess what's going on without the whole command line.

[apetrynet]

I noticed blender in there. Could it be related to #667?

[Tilix4]

My command line is very basic: python -m pip install --target /path/to/dir opentimelineio.

@apetrynet I've also tried with the Blender python, but I have the same issue with the windows python only, then Blender is not a topic for now ;)

[donquibeats]

I am getting the same error message under different circumstances. I'm using OpenTimelineIO 0.13.0 in a Python script, and using PyInstaller to bundle it up as an .exe for use around the studio. When bundled, running the .exe on a different machine throws this error:

File "venv\lib\site-packages\opentimelineio\opentime.py", line 1, in <module>
ImportError: DLL load failed: The specified module could not be found.

As far as I can tell (and I'm not confident about this), either PyInstaller or the frozen OpenTimelineIO code isn't coping properly with the relative path inherent in the line from . _opentime import (

Short of an update to OpenTimelineIO, might anyone be able to suggest an adjustment to this opentime.py file that would make it PyInstaller-friendly please? I'm not familiar with the structure of the code within site-packages/opentimelineio.

[reinecke]

@donquibeats pyinstaller can be a bit tricky. I think there is a way to unzip the contents of a pyinstaller archive, are you able to find the DLLs in there?
It's been a while, but last time I worked with pyinstaller I found that it had some setuptools tricks going on that sometimes could make it tough to ensure the extra non-puython resources would reliably be relocated into the package.

Also, which python version are you using to build the pyinstaller package?

[donquibeats]

Thanks for the responses. This is a Python 3.7 project, and PyInstaller creates a folder containing the .exe and a bunch of associated DLL's, but opentime.py and opentimelineio.py are not among them.

However, copying these DLL's manually from cxx-libs/bin into the same folder as the .exe doesn't fix the problem, unfortunately.

I'm not currently aware of how I would test whether the DLL's are bundled inside the .EXE.

Strangely, if we target OpenTimelineIO 0.11.0 then it works fine. This error only occurs if we target 0.12.x or 0.13.0. We can make it work if we accept the older version of OTIO (via pypi).

[apetrynet]

Strangely, if we target OpenTimelineIO 0.11.0 then it works fine. This error only occurs if we target 0.12.x or 0.13.0. We can make it work if we accept the older version of OTIO (via pypi).

0.11.0 was the last pure python release which is probably why it works out of the box. Other than that I'm afraid I can't be of any more help on this issue.

[donquibeats]

Thanks. Does the fact that 0.11.0 works give any indicators, either of what the problem might be, or of a possible workaround that we could use? For our current needs 0.11.0 is OK, but obviously we wouldn't want to be stuck on the older version forever.

[apetrynet]

Please excuse me if this is obvious to you :)
OTIO >=0.12.0 are based on a C++ core while <= 0.11.0 are strictly python based. The C++ based versions have python bindings built against library files. I think the main issue here is that the library files aren't installed to a location where python by default can get a hold of them.
To sum up. 0.11.0 is self contained while 0.12+ rely on library files (so or dll).

I believe @meshula is cooking up a cleaner install OTIO and the python bindings that hopefully will help.

[donquibeats]

That makes sense, thanks very much for the explanation.

In the short term, when I get time I will try again to use 0.13.0 via PyInstaller by embedding the two DLL files manually and adapting the import code, to see if I can put them somewhere that a PyInstaller-bundled Python can see them.

[reinecke]

Hey @donquibeats, here are a couple useful references for this stuff in pyinstaller:

• This tool may be able to help you inspect what got packaged in your .exe to see if stuff is missing
• If there is, in fact, something not being included that should be, the spec file may help with making sure those things get included

Forgive me if I'm covering stuff you already know. In my past struggles with PyInstaller, I remember these two bits being key for solving the problem I had.