With a development machine all set up for communicating in python with pyusb and libusb on Windows 10. The signed drivers are available, the device is communicating on the build machine. Building the installer on the development machine also is successful. Redistributing the installer built on the development machine delivers the expected experience.

The problem is when building on a Continuous Integration environment. PyInstaller builds an exe. InnoSetup builds a distributable installer. The installer is succesful. Then when running the installed application, you'll see the message:

Traceback (most recent call last):
  File "site-packages\usb\legacy.py", line 353, in busses
  File "site-packages\usb\core.py", line 1263, in find
  usb.core.NoBackendError: No backend available

There are many subtle differences between a typical windows 10 build environment and the Appveyor configuration. Here are the changes required to have an installer built on appveyor:

In setup.py, manually include pyusb:

requires = [

In appveyor configuration, manually include pyusb:

    - "set PATH=%MINICONDA%;%MINICONDA%\\Scripts;%PATH%" 
    - pip install pyusb

Straightforward to this point. Sure, appveyor should respect the setup.py requirement of pyusb, but for some reason it's not listed in conda list and pip freeze post install section. The workaround is to specify it manually.

Again, this works on the windows 10 development machine, but not on appveyor. The no backend available message is still present, but only on the appveyor install. Further googling of the error message shows that this problem has already been fixed. Thanks!

So all you need now is the development version of pyinstaller. Instructions say to install the development version of pyinstaller that includes the new usb hook like so:

(In appveyor.yml) - pip install https://github.com/pyinstaller/pyinstaller/archive/develop.zip

The above will cause a + to appear in the pyinstaller version suffix. This in turn will cause a ValueError when pyinstaller is run. But only on appveyor:

Traceback (most recent call last):
  File "C:\Miniconda\envs\conda_dash\Scripts\pyinstaller-script.py", line 6, in <module>
    from pkg_resources import load_entry_point
  File "C:\Miniconda\envs\conda_dash\lib\site-packages\pkg_resources.py", line 2850, in <module>
  File "C:\Miniconda\envs\conda_dash\lib\site-packages\pkg_resources.py", line 696, in require
    needed = self.resolve(parse_requirements(requirements))
  File "C:\Miniconda\envs\conda_dash\lib\site-packages\pkg_resources.py", line 566, in resolve
    requirements = list(requirements)[::-1]  # set up the stack
  File "C:\Miniconda\envs\conda_dash\lib\site-packages\pkg_resources.py", line 2650, in parse_requirements
    line, p, specs = scan_list(VERSION,LINE_END,line,p,(1,2),"version spec")
  File "C:\Miniconda\envs\conda_dash\lib\site-packages\pkg_resources.py", line 2628, in scan_list
    "Expected ',' or end-of-list in",line,"at",line[p:]
  ValueError: ("Expected ',' or end-of-list in", 'PyInstaller==3.3.dev0+483c819', 'at', '+483c819')

The fix is to strip out the commit hash suffix from the installed version number. Run setup.py with sdist first to insert just the major version number without the commit hash suffix.

  • pip uninstall -y pyinstaller
  • git clone https://github.com/pyinstaller/pyinstaller.git
  • cd pyinstaller
  • python setup.py sdist
  • python setup.py install
  • cd ..

This is still not enough. You'll need to include the libusb dll for use by the application. In the InnoSetup configuration file, include the line:

Source: "support_files\libusb_drivers\x86\libusb0_x86.dll"; \
DestDir: "{app}\dash\"; Flags: recursesubdirs ignoreversion