mayavi as "tons" of dependancies. you may run "pip install [path to mayavi wheel]" to captures the error messages describing all the wheels that may miss you. then download from cgohlke and install them first

also, you could say the same for holoviews that depends of "anaconda" stack, but WinPython implements most of "anaconda" stack, while mayavi is mainly "enthought" stack that is not included per default, as it was mostly Python-2.7 until very recently.

This is exactly what I did, installed using pip. That's when I saw the error messages. But I think WPCP should at least show a pop-up or something. Or do not remove the entry of the package in show the list with the packages to be installed and add "Failed" in red or something.

Currently the user is not informed at all and has do dig through the list of all installed packages and check if the package is there now or if the version has changed.

Does pip install have an exit code? Is it stated in the wheel somewhere in the install script?

WPCP was making sense when it was created, before "pip" birth date. Now, it's just a basic layer over "pip", that I keep until "pip" project and friends provide a graphical interface.

in french term, working on a graphical layer over pip myself would be "être plus royaliste que le roi".