nbconvert entry_points call failed due to [Errno 13] Permission denied: '/'

[SolomonJesurathinam]

Chaquopy version

13.0

Devices or emulators where the issue happens

Both Devices and Emulator

Relevant parts of your code

def process(content):
    import os,io
    from os.path import dirname, join

    content = bytes(content)
    filename = join(dirname(__file__), "filename1.ipynb")

    f = open(filename, 'wb')
    f.write(content)
    f.close()

    output = join(os.environ["HOME"])
    nbmain([filename,f"--output-dir={output}","--to=html","--template=classic"])

Describe your issue

It is failing when writing the file in output directory

Stack trace

FATAL EXCEPTION: main
Process: com.solomonj.chaquopytest, PID: 25412
com.chaquo.python.PyException: PermissionError: [Errno 13] Permission denied: '/'
	at <python>.pathlib.iterdir(pathlib.py:1122)
	at <python>.java.android.importer.find_distributions(.\java\android\importer.py:330)
	at <python>.importlib_metadata._itertools.unique_everseen(_itertools.py:15)
	at <python>.importlib_metadata.<genexpr>(__init__.py:853)
	at <python>.importlib_metadata.entry_points(__init__.py:856)
	at <python>.nbconvert.exporters.base.get_exporter(base.py:104)
	at <python>.nbconvert.nbconvertapp.convert_notebooks(nbconvertapp.py:594)
	at <python>.nbconvert.nbconvertapp.start(nbconvertapp.py:426)
	at <python>.traitlets.config.application.launch_instance(application.py:982)
	at <python>.jupyter_core.application.launch_instance(application.py:276)
	at <python>.test.process(test.py:20)
	at <python>.chaquopy_java.call(chaquopy_java.pyx:379)
	at <python>.chaquopy_java.Java_com_chaquo_python_PyObject_callAttrThrowsNative(chaquopy_java.pyx:351)
	at com.chaquo.python.PyObject.callAttrThrowsNative(Native Method)
	at com.chaquo.python.PyObject.callAttrThrows(PyObject.java:232)
	at com.chaquo.python.PyObject.callAttr(PyObject.java:221)
	at com.solomonj.chaquopytest.MainActivity$2.onActivityResult(MainActivity.java:81)
	at com.solomonj.chaquopytest.MainActivity$2.onActivityResult(MainActivity.java:59)
	at androidx.activity.result.ActivityResultRegistry$1.onStateChanged(ActivityResultRegistry.java:149)
	at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:360)
	at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.java:271)
	at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.java:313)
	at androidx.lifecycle.LifecycleRegistry.moveToState(LifecycleRegistry.java:151)
	at androidx.lifecycle.LifecycleRegistry.handleLifecycleEvent(LifecycleRegistry.java:134)
	at androidx.lifecycle.ReportFragment.dispatch(ReportFragment.java:68)
	at androidx.lifecycle.ReportFragment$LifecycleCallbacks.onActivityPostStarted(ReportFragment.java:187)
	at android.app.Activity.dispatchActivityPostStarted(Activity.java:1279)
	at android.app.Activity.performStart(Activity.java:7968)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3332)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2044)
	at android.os.Handler.dispatchMessage(Handler.java:107)
	at android.os.Looper.loop(Looper.java:224)
	at android.app.ActivityThread.main(ActivityThread.java:7560)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

[mhsmith]

Please post the python section from your build.gradle file, along with any requirements files it refers to.

[mhsmith]

And please show how nbmain was initialized, as that doesn't seem to be a public API.

[SolomonJesurathinam]

Build Gradle file

ndk {
            abiFilters "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
        }
        python {
            version "3.8"
            pip{
                install "-r", "requirements.txt"
            }
        }

requirements

asttokens==2.1.0
attrs==22.1.0
backcall==0.2.0
beautifulsoup4==4.11.1
bleach==5.0.1
colorama==0.4.6
decorator==5.1.1
defusedxml==0.7.1
entrypoints==0.4
executing==1.2.0
fastjsonschema==2.16.2
ipython==8.6.0
jedi==0.18.2
Jinja2==3.1.2
jsonschema==4.17.1
jupyter_client==7.2.0
jupyter_core==5.0.0
jupyterlab-pygments==0.2.2
MarkupSafe==2.1.1
matplotlib-inline==0.1.6
mistune==2.0.4
nbclient==0.7.0
nbconvert==7.2.5
nbformat==5.7.0
nest-asyncio==1.5.6
packaging==21.3
pandocfilters==1.5.0
parso==0.8.3
pickleshare==0.7.5
platformdirs==2.5.4
prompt-toolkit==3.0.33
pure-eval==0.2.2
Pygments==2.13.0
pyparsing==3.0.9
pyrsistent==0.19.2
python-dateutil==2.8.2
pyzmq==18.1.1
six==1.16.0
soupsieve==2.3.2.post1
stack-data==0.6.1
tinycss2==1.2.1
tornado==6.2
traitlets==5.5.0
wcwidth==0.2.5
webencodings==0.5.1

nbmain was initialized from nbconvert

import nbconvert.nbconvertapp
from nbconvert.nbconvertapp import main as nbmain

[mhsmith]

For some reason, nbconvert unconditionally adds the working directory to the start of sys.path. But the default working directory on Android is the root directory, which is unreadable.

We'll make Chaquopy handle this situation better in the next version. Meanwhile, you can work around it by running the following before importing nbconvert:

import os
os.chdir(os.environ["HOME"])

[mhsmith]

Notes for next version: find_distributions should be able to deal with this by simply skipping over any unreadable directories. os.access(R_OK | X_OK) will probably not work, because the directory is made unreadable using SELinux, not normal permissions, so we'll just have to try reading it and catch the exception.

Since this method is contained in a meta-path finder, it should be the only part of our import system which ever sees paths outside of the AssetFinder directory. Having / at the start of sys.path doesn't seem to impede normal imports, but we should add a test for that as well.

[mhsmith]

This issue was fixed in Chaquopy 14.0.2. To upgrade, edit your app's top-level build.gradle file and change the version number of com.chaquo.python.