Webview bootstrap can't find 'org.jnius.NativeInvocationHandler'.

[kollivier]

Versions

• Python: 3.7 / 3.8
• OS: Ubuntu 18.04
• Kivy: N/A
• Cython: 0.29.16

Description

While attempting to update a p4a project to the latest version, I discovered that the webview bootstrap is apparently no longer able to load org.jnius.NativeInvocationHandler, which breaks some jnius functionality like PythonJavaClass that our app relies on.

Here is a minimal sample with buildozer.spec and a main.py that shows the problem (the error message should show up in adb logcat logs):

jnius_webview.zip

This sample runs and does not give the error when using the SDL2 bootstrap.

Note also that the example uses the release-2019.10.06 branch of p4a because the latest master branch has an issue with webview bootstrap not having Python 3.8 support, and latest develop ran into an error in the p4a build scripts about a missing method. (Sorry, I forgot to copy it before running more tests and lost it.)

It does reproduce under latest master though with the Python 3.8 issue fixed, and on develop if using p4a commands to build instead of buildozer.

buildozer.spec

Command:

buildozer android debug deploy run

Spec file:

See attached zip.

Logs

04-13 20:50:14.669 23205 23254 I python : Android kivy bootstrap done. name is main
04-13 20:50:14.669 23205 23254 I python : AND: Ran string
04-13 20:50:14.669 23205 23254 I python : Run user program, change dir and execute entrypoint
04-13 20:50:14.757 23205 23254 I python : ERROR:root:Hello world!
04-13 20:50:14.779 23205 23254 I python : Traceback (most recent call last):
04-13 20:50:14.779 23205 23254 I python : File "/home/kevino/code/webview_sample/.buildozer/android/app/main.py", line 9, in
04-13 20:50:14.779 23205 23254 I python : File "/home/kevino/code/webview_sample/.buildozer/android/platform/build-armeabi-v7a/build/python-installs/myapp/jnius/reflect.py", line 159, in autoclass
04-13 20:50:14.780 23205 23254 I python : File "jnius/jnius_export_func.pxi", line 26, in jnius.jnius.find_javaclass
04-13 20:50:14.780 23205 23254 I python : jnius.jnius.JavaException: Class not found b'org/jnius/NativeInvocationHandler'
04-13 20:50:14.780 23205 23254 I python : Python for android ended.

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