[PyQt] QML plugins - AttributeError: module 'PyQt5' has no attribute 'sip'

[Kyle Altendorf]

Phil,

Aside from debugging my problem, how do you feel about the second patch? 
  I don't know my way around the C-API and the docs don't make it clear 
to me if the 'pre-import' should be required...  but it doesn't seem 
like I should be able to do anything outside that would cause the 
AttributeError.

Cheers,
-kyle


On 2020-03-07 23:46, Kyle Altendorf wrote:
> I'm working on catching up pyqt5-tools [0] with the new build system
> for PyQt5.  I have it building and working in some cases.  The present
> issue I am trying to address is the failure of my simple tests of the
> QML plugins when running in GitHub Actions.  If I download the wheel
> the build generates and tests against (as far as I know...) it works
> fine locally.  On the server I get an error [1].
> 
>     AttributeError: module 'PyQt5' has no attribute 'sip'
> 
> I tried patching qmlscene/pluginloader.cpp [2].
> 
>     diff --git a/qmlscene/pluginloader.cpp b/qmlscene/pluginloader.cpp
>     index 635d31e..5c33b1f 100644
>     --- a/qmlscene/pluginloader.cpp
>     +++ b/qmlscene/pluginloader.cpp
>     @@ -412,9 +412,9 @@ PyObject *PyQt5QmlPlugin::getModuleAttr(const
> char *module, const char *attr)
>     void PyQt5QmlPlugin::getSipAPI()
>     {
>     #if defined(SIP_USE_PYCAPSULE)
>     -    sip = (const sipAPIDef *)PyCapsule_Import("PyQt5.sip._C_API", 
> 0);
>     +    sip = (const sipAPIDef 
> *)PyCapsule_Import("PyQt5.a_sip._C_API", 0);
>     #else
>     -    PyObject *c_api = getModuleAttr("PyQt5.sip", "_C_API");
>     +    PyObject *c_api = getModuleAttr("PyQt5.b_sip", "_C_API");
> 
>         if (c_api)
>         {
> 
> The patched `a_sip` was triggered in CI [3] but not locally.  Maybe
> that means that somehow Python is getting initialized previously when
> run locally somehow?  (based on the PyQt5QmlPlugin constructor)  Or I
> really am not running the same thing locally?  I tried a few things
> without any apparent knowledge gain.  I'll hope someone here has some
> insight and stop for now with my most recent attempt [4].
> 
>     diff --git a/qmlscene/pluginloader.cpp b/qmlscene/pluginloader.cpp
>     index 635d31e..d6acd6e 100644
>     --- a/qmlscene/pluginloader.cpp
>     +++ b/qmlscene/pluginloader.cpp
>     @@ -412,6 +412,16 @@ PyObject *PyQt5QmlPlugin::getModuleAttr(const
> char *module, const char *attr)
>     void PyQt5QmlPlugin::getSipAPI()
>     {
>     #if defined(SIP_USE_PYCAPSULE)
>     +    PyObject *mod = PyImport_ImportModule("PyQt5.sip");
>     +    if (!mod)
>     +    {
>     +        PyErr_Print();
>     +        return;
>     +    }
>     +    else
>     +    {
>     +        Py_DECREF(mod);
>     +    }
>         sip = (const sipAPIDef *)PyCapsule_Import("PyQt5.sip._C_API", 
> 0);
>     #else
>         PyObject *c_api = getModuleAttr("PyQt5.sip", "_C_API");
> 
> This eliminates the error but still fails my tests in CI [5].  The
> tests [6] basically just check for some reference data to be written
> to files by my custom examples when the PyQt5 plugins handle them.
> 
> Thanks for any help that you can offer.
> 
> Cheers,
> -kyle
> 
> 
> [0] https://github.com/altendky/pyqt5-tools/pull/41
> 
> [1]
> https://gist.githubusercontent.com/altendky/53479b3a57069453f5511b7e02a2e4fd/raw/7bbf58c3d518ea27443eee518e7efa46802d61c4/gistfile1.txt
> 
> [2]
> https://github.com/altendky/pyqt5-tools/pull/41/commits/4c72f778afce88c8e68e25fcfad616c2e8b9eec1#diff-44b7c383d27b03d3ef422f5aa45078c5
> 
> [3]
> https://gist.githubusercontent.com/altendky/b3d77b52aaa785ed980c7682aaa07f07/raw/b313c3945202cdaae67387cdfd9b5667e1808322/gistfile1.txt
> 
> [4]
> https://github.com/altendky/pyqt5-tools/commit/2494b3decf161f49b86174615960610d1078ff03
> 
> [5]
> https://gist.githubusercontent.com/altendky/7082b1301aa3c0cf162024d37e52ae72/raw/6e4faa3b484f9d95727b8bbd5399b90d660ab8b9/gistfile1.txt
> 
> [6]
> https://github.com/altendky/pyqt5-tools/blob/2494b3decf161f49b86174615960610d1078ff03/src/pyqt5_tools/tests/test_entrypoints.py