r"""
This is a sage-on-gentoo stub. The functionality usually found in this file
is not compatible with the management of sage by portage.
"""

#*****************************************************************************
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#                  http://www.gnu.org/licenses/
#*****************************************************************************
from __future__ import print_function
import os

def is_package_installed(package):
    """
    Return False in sage-on-gentoo
    """
    return False

class PackageNotFoundError(RuntimeError):
    """
    This class defines the exception that should be raised when a
    function, method, or class cannot detect a Sage package that it
    depends on.

    This exception should be raised with a single argument, namely
    the name of the package.

    When an ``PackageNotFoundError`` is raised, this means one of the
    following:

    - The required optional package is not installed.

    - The required optional package is installed, but the relevant
      interface to that package is unable to detect the package.

    EXAMPLES::

        sage: from sage.misc.package import PackageNotFoundError
        sage: raise PackageNotFoundError("my_package")
        Traceback (most recent call last):
        ...
        PackageNotFoundError: the package 'my_package' was not found. It may or may not be available in portage
    """
    def __str__(self):
        """
        Return the actual error message.

        EXAMPLES::

            sage: from sage.misc.package import PackageNotFoundError
            sage: str(PackageNotFoundError("my_package"))
            "the package 'my_package' was not found. It may or may not be available in portage"
        """
        return ("the package {0!r} was not found. "
            "It may or may not be available in portage"
            .format(self.args[0]))

def is_package_installed_and_updated(pkg: str) -> bool:

    import os
    condition = os.getenv('WANT_%s'%pkg,False)
    return condition