How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found."

volcano_56782 · 14 Jan 2022, 06:13

Hi,

I have built a python program with a GUI (PyQt5) and wanted to make it into an .app for macOS. I have chosen Py2App to do this.

When creating a .app with Alias Mode in Py2App the app works fine, however, when I create the bundled version of the app, the app tries to launch but crashes.

I tried opening this app from the terminal and got this error:

(planner_venv) Febins-MacBook-Pro:v1.2 - Planner Builder Febin.J$ ./dist/Planner\ Builder.app/Contents/MacOS/Planner\ Builder  qt.qpa.plugin: Could not load the Qt platform plugin "cocoa" in "" even though it was found. 
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.  Available platform plugins are: cocoa, minimal, offscreen, webgl.  
Abort trap: 6

I am using Python 3.10.1. Py2App 0.26.1. PyQt5 5.15.6. I am MacOS 12.1

jsulm · 14 Jan 2022, 06:31

@volcano_56782 Before starting the app from terminal set QT_DEBUG_PLUGINS variable to a non-zero value. You will then see more debug output, post it here.
See https://doc.qt.io/qt-5/debug.html

volcano_56782 · 14 Jan 2022, 06:34

@jsulm Hi, I am not that knowledgeable in Qt and coding. Could you please tell me how to set QT_DEBUG_PLUGINS variable to a non-zero value? Do I do it in the code or somewhere else? Sorry if this is an oblivious question.

jsulm · 14 Jan 2022, 07:21

@volcano_56782 Has nothing to do with Qt. Just how a variable is set in terminal.

export QT_DEBUG_PLUGINS=1
./YOUR_APP

volcano_56782 · 14 Jan 2022, 07:49

@jsulm said in How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found.":

export QT_DEBUG_PLUGINS=1
./YOUR_APP

Thank you. I tried this and got this very long output:

QFactoryLoader::QFactoryLoader() checking directory path "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "cocoa"
        ]
    },
    "archreq": 0,
    "className": "QCocoaIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("cocoa")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqminimal.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqminimal.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqoffscreen.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqoffscreen.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqwebgl.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqwebgl.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() checking directory path "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqcocoa.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqcocoa.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "cocoa"
        ]
    },
    "archreq": 0,
    "className": "QCocoaIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("cocoa")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqminimal.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqminimal.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqoffscreen.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqoffscreen.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqwebgl.dylib"
Found metadata in lib /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/plugins/platforms/libqwebgl.dylib, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331264
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() checking directory path "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/platforms" ...
Cannot load library /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib: (dlopen(/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib, 0x0085): Library not loaded: @rpath/QtDBus.framework/Versions/5/QtDBus
  Referenced from: /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib
  Reason: tried: '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/../../lib/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/../../lib/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/lib/QtCore.framework/Versions/5/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Library/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/System/Library/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file))
QLibraryPrivate::loadPlugin failed on "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib" : "Cannot load library /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib: (dlopen(/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib, 0x0085): Library not loaded: @rpath/QtDBus.framework/Versions/5/QtDBus\n  Referenced from: /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib\n  Reason: tried: '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/../../lib/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/../../lib/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/MacOS/../Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Resources/lib/python3.10/PyQt5/Qt/lib/QtCore.framework/Versions/5/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/Library/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file), '/System/Library/Frameworks/QtDBus.framework/Versions/5/QtDBus' (no such file))"
qt.qpa.plugin: Could not load the Qt platform plugin "cocoa" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: cocoa, minimal, offscreen, webgl.

Abort trap: 6

I'm not sure what all this means though

jsulm · 14 Jan 2022, 07:56

@volcano_56782 said in How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found.":

I'm not sure what all this means though

Well, you need to search for cocoa there.
What I see:
Cannot load library /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib: (dlopen(/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib, 0x0085): Library not loaded: @rpath/QtDBus.framework/Versions/5/QtDBus

You seem to use paths with blanks, you should avoid that.
Does /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib exist?
Also, it seems that cocoa plug-in requires DBus.

volcano_56782 · 14 Jan 2022, 08:41

@jsulm said in How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found.":

Does /Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/plugins/platforms/libqcocoa.dylib exist?

No, this does not exist. How can I get DBus?

volcano_56782 · J jsulm 14 Jan 2022, 07:49

@jsulm Also, I forgot to say that the app runs perfectly in alias mode, the issue only occurs when I try to compile the app for distribution

jsulm · 14 Jan 2022, 09:26

@volcano_56782 said in How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found.":

How can I get DBus?

As far as I know DBus is not used on Mac, so don't know why cocoa plug-in wants it.
Maybe somebody with more MacOS expertise can help.

volcano_56782 · J jsulm 14 Jan 2022, 08:41

@jsulm Hopefully, I have been stuck on this for days

hskoglund · wrote on 14 Jan 2022, 19:28

Hi, for Qt 5..15.2 in Terminal, if you do a
otool -L libqcocoa.dylib it lists 5 dlls it needs, one of them is:
@rpath/QtDBus.framework/Versions/5/QtDBus
(and if you build a vanilla Hello World widget app in Qt. 5.15.2 QtDBus is used).

Maybe when you compiled your app for distribution, perhaps that QtDbus dll didn't get copied? You can try copy it manually, start a Terminal and type:

cp -r ~/Qt/5.15.2/clang_64/lib/QtDBus.framework "/Users/Febin.J/Documents/Projects/Python Projects/v1.2 - Planner Builder/dist/Planner Builder.app/Contents/Frameworks"

Note: you'll need the quotes since you have spaces in your app path.

JimboNiss · 28 Jan 2022, 19:28

I've got this same problem, when using py2app to compose a python Qt application. I can run the application from the py2app dist folder, just fine. However, after I copy it to /Applications, I get the same error...

Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() checking directory path "/Applications/englauncher.app/Contents/MacOS/platforms" ...
Cannot load library /Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib: (dlopen(/Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib, 133): Library not loaded: @rpath/QtDBus.framework/Versions/5/QtDBus
Referenced from: /Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib
Reason: image not found)
QLibraryPrivate::loadPlugin failed on "/Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib" : "Cannot load library /Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib: (dlopen(/Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib, 133): Library not loaded: @rpath/QtDBus.framework/Versions/5/QtDBus\n Referenced from: /Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib\n Reason: image not found)"
qt.qpa.plugin: Could not load the Qt platform plugin "cocoa" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: cocoa, minimal, offscreen, webgl.

Anyone have any ideas?

SGaist · 28 Jan 2022, 19:46

@JimboNiss hi and welcome to devnet,

What exactly do you have in your py2app folder ?
Do you have the QDbus framework in your app bundle ?

JimboNiss · S SGaist 28 Jan 2022, 19:28

@SGaist, not sure what you are asking, but I just updated py2app via pip3, as a test. Didn't help. Here is my setup.py for it:

"""
This is a setup.py script generated by py2applet

Usage:
python setup.py py2app
"""

from setuptools import setup

APP = ['englauncher.py']
DATA_FILES = [('', ['applescript'])]
#DATA_FILES = []
OPTIONS = {
'iconfile': 'icon_SEO.icns',
'packages': ['cffi']
}

setup(
app=APP,
data_files=DATA_FILES,
options={'py2app': OPTIONS},
setup_requires=['py2app'],
)

The QtDBus directory is in both /Applications/<app> and the py2app created ./disk/<app>...

Jims-MacBook-Pro:englauncher3 $ sudo find /Applications -name "QtDBus"
Password:
/Applications/englauncher.app/Contents/Resources/lib/python3.9/PyQt5/bindings/QtDBus
/Applications/englauncher.app/Contents/Resources/lib/python3.9/PyQt5/Qt5/lib/QtDBus.framework/Versions/5/QtDBus
Jims-MacBook-Pro:englauncher3 $ sudo find ./dist -name "QtDBus"
./dist/englauncher.app/Contents/Resources/lib/python3.9/PyQt5/Qt5/lib/QtDBus.framework/Versions/5/QtDBus
./dist/englauncher.app/Contents/Resources/lib/python3.9/PyQt5/bindings/QtDBus

SGaist · 28 Jan 2022, 21:55

Can you check the rpath values of the executable ?

See here for more information about it.

JimboNiss · S SGaist 28 Jan 2022, 20:07

@SGaist said in How to solve "Could not load the Qt platform plugin "cocoa" in "" even though it was found.":

here

Ok, I was able to locate the rpath...

Jims-MacBook-Pro:englauncher3 $ otool -L ./dist/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib |grep -i qtdbus
@rpath/QtDBus.framework/Versions/5/QtDBus (compatibility version 5.15.0, current version 5.15.2)

Jims-MacBook-Pro:englauncher3 $ otool -L /Applications/englauncher.app/Contents/plugins/platforms/libqcocoa.dylib |grep -i qtdbus
@rpath/QtDBus.framework/Versions/5/QtDBus (compatibility version 5.15.0, current version 5.15.2)

https://stackoverflow.com/questions/12521802/print-rpath-of-an-executable-on-macos/12522096#125220
Jims-MacBook-Pro:englauncher3 $ otool -l dist/englauncher.app/Contents/MacOS/englauncher | grep RPATH -A2
cmd LC_RPATH
cmdsize 48
path @executable_path/../Frameworks (offset 12)
Jims-MacBook-Pro:englauncher3 $ otool -l dist/englauncher.app/Contents/MacOS/englauncher
Jims-MacBook-Pro:englauncher3 $ otool -l /Applications/englauncher.app/Contents/MacOS/englauncher | grep RPATH -A2
cmd LC_RPATH
cmdsize 48
path @executable_path/../Frameworks (offset 12)

Jims-MacBook-Pro:englauncher3 $ ls dist/englauncher.app/Contents/Frameworks
Python.framework libcrypto.1.1.dylib liblzma.5.dylib libmpdec.2.5.1.dylib libmpdec.3.dylib libssl.1.1.dylib
Jims-MacBook-Pro:englauncher3 $ ls /Applications/englauncher.app/Contents/Frameworks
Python.framework libcrypto.1.1.dylib liblzma.5.dylib libmpdec.2.5.1.dylib libmpdec.3.dylib libssl.1.1.dylib

What's odd is I can run the application from the dist directory just fine:
./dist/englauncher.app/Contents/MacOS/englauncher

But, I get the error when running it from /Applications:
/Applications/englauncher.app/Contents/MacOS/englauncher

I copied the application from ./dist to /Applications, so they should be the same.

hskoglund · 28 Jan 2022, 23:09

HI, just guessing but maybe your app is picking up the QtDBus dylib from another place outside of your englauncher.app directory (and using relative paths).
To check, could you launch your app from the dist directory (i.e. where it runs successfully) and then open a Terminal and type
lsof -c englauncher
this will show what dlls/dylibs are loaded (and most importantly their paths).

JimboNiss · wrote on 28 Jan 2022, 23:09

@hskoglund, the process doesn't keep running, so not sure I can run lsof on it.

Another thing I tried is completely uninstalling python3 from brew repository, and reinstalling it directly from python3, using Mac disk image. Had to reinstall my pip libraries, and got the same exact issue.

I'm at my wits end with this, and think it's a Big Sur issue, though can't prove it.

hskoglund · 31 Jan 2022, 15:59

Hi, one way stop your app from exiting, you could try showing a message box, for example like this:

...
app = QApplication([])
alert = QMessageBox()
alert.setText('Click me when lsof -c is done')
alert.exec()
...

then you should have time to do a lsof -c englauncher

JimboNiss · wrote on 31 Jan 2022, 15:59

@hskoglund, that didn't help, as it's not even able to load the Qt libraries. I even created a simple test app with your code, and while I can run it from ./dist/testapp, as soon as I copy it to /Applications, it fails loading the libraries in the same way.