[PyQt] fail to load libqcocoa.dylib on sandboxed OSX PyQt app

[Phil Thompson]

On 05/06/2014 4:26 pm, lloyd konneker wrote:
> I have built a sandboxed PyQt app on OSX (pyqtdeploy, convert to Xcode
> proj, macdeployqt inside Xcode, ...Product>Archive). That all seems to
> work: the bundle is complete and includes an appropriate qt.conf (and
> is sandboxed and codesigned.)
> 
> But I think I also need to have a preamble to my app to
> addLibraryPath() to plugins:
> 
> def _appBundlePluginPath():
>   '''
>   path to plugin component of OSX app's bundle
>   or None
>   '''
>   # use Python os, class method QCoreApplication.applicationDirPath()
> cannot be used until QCoreApplication is instantiated?
>   appPath = _appBundlePath()
>   # Typically "APP_DIR/Contents/MacOS" on OSX.
>   # else is path that usually does not have a Plugins sub dir
>   appDir = QDir(appPath)
>   if not appDir.cdUp():
>     logAlert("Failed cdUp from appDir")
>   # assert like ../Contents
>   if appDir.cd("PlugIns"):
>     result = appDir.absolutePath()
>     # assert like ../Contents/PlugIns
>   else:
>     result = None
>   return result
> 
> def _appBundlePath():
>   '''
>   This returns a strange path for sandboxed apps '.../:/...'.
>   I don't understand what the colon means
>   '''
>   return os.path.dirname(os.path.abspath( __file__ ))
> 
> But the cdUp() fails because of the colon in the strange path?

The colon is what Qt uses to identify a file in a resource file. 
Obviously the Python stdlib doesn't understand those so use QFile and 
QDir when computing locations relative to __file__. However, in this 
case, I don't see how __file__ would be related to the bundle path - 
applicationDirPath() seems more sensible.

> Should I give up and link libqcocoa statically (I am loathe to build
> Qt on OSX) or  is there some way to get a proper path to plugins in
> the sandbox?
> 
> (Or is addLibraryPath() even necessary, does Qt read qt.conf first and
> is it working on sandboxed apps?)
> 
> (Is the strange path related to chroot, can I somehow fabricate an
> absolute path to the plugins directory, and will sandboxing let Qt
> access it?)

Phil