[petsc-dev] BuildSystem help needed

[Barry Smith]

   Matt,

   When a user provides --download-packagename for any package that does not support --download-   configure silently ignores their request leading the user to think that it actually did download the package.

   This is because in package.py there is the code

  def checkDownload(self, requireDownload = 1):
    '''Check if we should download the package, returning the install directory or the empty string indicating installation'''
    if not self.download:
      return ''

   I naively thought I could simple add a check if the user provided --download-package but self.download was not supported it would error out with a useful error message. That proved impossible.

   Could you please add something to BuildSystem so that if a user requests --download-packagename but that functionality is not supported it generates a nice error message, in particular this needs to work for --download-thrust --download-cusp and --download-cuda but there are many others as well.

    Thanks

    Barry