"TypeError: 'ObjCInstance' object is not callable" on macOS High Sierra

In High Sierra (macOS 10.13), I am unable to use Toga or Toga-demo due to a TypeError. I was able to duplicate this on a fresh install of High Sierra in a VM; when I installed Toga and Toga-demo on a fresh install of Sierra (10.12), Toga and Toga-demo worked with no issues.

This has similar symptoms as issue https://github.com/pybee/toga/issues/154, but downgrading Rubicon has not solved the problem.

Details

Python Installation

$ uname -a
Darwin Andrews-Mac.local 17.0.0 Darwin Kernel Version 17.0.0: Thu Aug 24 21:48:19 PDT 2017; root:xnu-4570.1.46~2/RELEASE_X86_64 x86_64
$
$ gcc --version
Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 9.0.0 (clang-900.0.37)
Target: x86_64-apple-darwin17.0.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
$
$ CFLAGS="-I$(brew --prefix openssl)/include -O3" \
LDFLAGS="-L$(brew --prefix openssl)/lib" \
env PYTHON_CONFIGURE_OPTS="--enable-framework" pyenv install -v 3.6.3
...
Installed Python-3.6.3 to /Users/ame/.pyenv/versions/3.6.3
$ 
$ pyenv shell 3.6.3
$
$ python -V -V
Python 3.6.3 (default, Oct  9 2017, 17:43:29) 
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.37)]

Virtualenv

$ python -m venv .venv
$
$ source .venv/bin/activate
$
$ pip install toga toga-demo
Collecting toga
  Downloading toga-0.2.15-py3-none-any.whl
Collecting toga-demo
  Downloading toga_demo-0.2.15-py3-none-any.whl
Collecting toga-cocoa; sys_platform == "darwin" (from toga)
  Downloading toga_cocoa-0.2.15-py3-none-any.whl
Collecting toga-core>=0.2.15 (from toga-cocoa; sys_platform == "darwin"->toga)
  Downloading toga_core-0.2.15-py3-none-any.whl (413kB)
    100% |████████████████████████████████| 419kB 2.6MB/s 
Collecting rubicon-objc>=0.2.8 (from toga-cocoa; sys_platform == "darwin"->toga)
  Downloading rubicon_objc-0.2.8-py3-none-any.whl
Collecting colosseum>=0.1.6 (from toga-core>=0.2.15->toga-cocoa; sys_platform == "darwin"->toga)
  Downloading colosseum-0.1.6-py3-none-any.whl
Installing collected packages: colosseum, toga-core, rubicon-objc, toga-cocoa, toga, toga-demo
Successfully installed colosseum-0.1.6 rubicon-objc-0.2.8 toga-0.2.15 toga-cocoa-0.2.15 toga-core-0.2.15 toga-demo-0.2.15

First Attempt

$ toga-demo
Traceback (most recent call last):
  File "/Users/ame/workspace/org.elgert/toga/.venv/bin/toga-demo", line 11, in <module>
    sys.exit(run())
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/__main__.py", line 5, in run
    main().main_loop()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 167, in main_loop
    self._startup()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 95, in _startup
    self._impl = NSApplication.sharedApplication()
TypeError: 'ObjCInstance' object is not callable
$ 
$ python
Python 3.6.3 (default, Oct  9 2017, 17:43:29) 
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.37)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from rubicon.objc import *                        
>>> NSBundle = ObjCClass('NSBundle')           
>>> NSBundle.mainBundle()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'ObjCInstance' object is not callable
>>> exit()

Downgrade Rubicon

Rubicon-objc==0.2.7

$ pip install rubicon-objc==0.2.7
Collecting rubicon-objc==0.2.7
  Downloading rubicon_objc-0.2.7-py3-none-any.whl
Installing collected packages: rubicon-objc
  Found existing installation: rubicon-objc 0.2.8
    Uninstalling rubicon-objc-0.2.8:
      Successfully uninstalled rubicon-objc-0.2.8
Successfully installed rubicon-objc-0.2.7
$
$ toga-demo
Traceback (most recent call last):
  File "/Users/ame/workspace/org.elgert/toga/.venv/bin/toga-demo", line 11, in <module>
    sys.exit(run())
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/__main__.py", line 5, in run
    main().main_loop()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 167, in main_loop
    self._startup()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 95, in _startup
    self._impl = NSApplication.sharedApplication()
TypeError: 'ObjCInstance' object is not callable

Rubicon-objc==0.2.6

$ pip install rubicon-objc==0.2.6
Collecting rubicon-objc==0.2.6
  Downloading rubicon_objc-0.2.6-py3-none-any.whl
Installing collected packages: rubicon-objc
  Found existing installation: rubicon-objc 0.2.7
    Uninstalling rubicon-objc-0.2.7:
      Successfully uninstalled rubicon-objc-0.2.7
Successfully installed rubicon-objc-0.2.6
$
$ toga-demo
Traceback (most recent call last):
  File "/Users/ame/workspace/org.elgert/toga/.venv/bin/toga-demo", line 7, in <module>
    from toga_demo.__main__ import run
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/__main__.py", line 2, in <module>
    from toga_demo.app import main
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/app.py", line 4, in <module>
    import toga
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga/__init__.py", line 114, in <module>
    set_platform()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga/__init__.py", line 86, in set_platform
    local_vars['platform'] = importlib.import_module(module_name)
  File "/Users/ame/.pyenv/versions/3.6.3/Python.framework/Versions/3.6/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/__init__.py", line 2, in <module>
    from .app import *
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 8, in <module>
    from .command import Command, Group
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/command.py", line 3, in <module>
    from .widgets.icon import Icon
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/widgets/icon.py", line 4, in <module>
    from ..libs import NSImage
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/libs/__init__.py", line 1, in <module>
    from .appkit import *
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/libs/appkit.py", line 232, in <module>
    NSColor.declare_class_property('alternateSelectedControlColor')
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/rubicon/objc/objc.py", line 1300, in __getattr__
    raise AttributeError('%s.%s %s has no attribute %s' % (type(self).__module__, type(self).__qualname__, self.objc_class.name, name))
AttributeError: rubicon.objc.objc.ObjCClass NSColor has no attribute declare_class_property

Rubicon-objc==0.2.4

$ pip install rubicon-objc==0.2.4
Collecting rubicon-objc==0.2.4
  Downloading rubicon_objc-0.2.4-py3-none-any.whl
Installing collected packages: rubicon-objc
  Found existing installation: rubicon-objc 0.2.6
    Uninstalling rubicon-objc-0.2.6:
      Successfully uninstalled rubicon-objc-0.2.6
Successfully installed rubicon-objc-0.2.4
$
$ toga-demo
Traceback (most recent call last):
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/rubicon/objc/objc.py", line 1274, in __getattr__
    return self.__dict__[name]
KeyError: 'declare_class_property'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/ame/workspace/org.elgert/toga/.venv/bin/toga-demo", line 7, in <module>
    from toga_demo.__main__ import run
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/__main__.py", line 2, in <module>
    from toga_demo.app import main
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_demo/app.py", line 4, in <module>
    import toga
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga/__init__.py", line 114, in <module>
    set_platform()
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga/__init__.py", line 86, in set_platform
    local_vars['platform'] = importlib.import_module(module_name)
  File "/Users/ame/.pyenv/versions/3.6.3/Python.framework/Versions/3.6/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/__init__.py", line 2, in <module>
    from .app import *
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/app.py", line 8, in <module>
    from .command import Command, Group
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/command.py", line 3, in <module>
    from .widgets.icon import Icon
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/widgets/icon.py", line 4, in <module>
    from ..libs import NSImage
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/libs/__init__.py", line 1, in <module>
    from .appkit import *
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/toga_cocoa/libs/appkit.py", line 232, in <module>
    NSColor.declare_class_property('alternateSelectedControlColor')
  File "/Users/ame/workspace/org.elgert/toga/.venv/lib/python3.6/site-packages/rubicon/objc/objc.py", line 1277, in __getattr__
    raise AttributeError('ObjCClass %s has no attribute %s' % (self.name, name))
AttributeError: ObjCClass NSColor has no attribute declare_class_property

[freakboy3742]

@jfunez Unfortunately, the instructions @dgelessus gave won’t work - the Toga repository contains a number of sub-packages, and there’s no way to install the sub-packages directly from git. If you look at your pip freeze output, you’ve got an updated toga - but not toga-cocoa or toga-core, which is where the important bits are.

To install the development version of Toga, you need to run:

$ git clone https:///github.com/pybee/toga.git
$ cd toga
$ pip install src/core
$ pip install src/cocoa

[freakboy3742]

This has been corrected with Rubicon 0.2.10.