How to use crossenv - 10 common examples

system_site_packages=False,
                clear=self.clear_cross,
                symlinks=True,
                upgrade=False,
                with_pip=False)
        env.create(context.cross_env_dir)
        context.cross_bin_path = os.path.join(context.cross_env_dir, 'bin')
        context.cross_env_exe = os.path.join(
                context.cross_bin_path, context.python_exe)
        context.cross_cfg_path = os.path.join(context.cross_env_dir, 'pyvenv.cfg')
        context.cross_activate = os.path.join(context.cross_bin_path, 'activate')

        # Remove binaries. We'll run from elsewhere
        for exe in os.listdir(context.cross_bin_path):
            if not exe.startswith('activate'):
                utils.remove_path(os.path.join(context.cross_bin_path, exe))

        # Alter pyvenv.cfg
        with utils.overwrite_file(context.cross_cfg_path) as out:
            with open(context.cross_cfg_path) as inp:
                for line in inp:
                    if line.split()[0:2] == ['home', '=']:
                        line = 'home = %s\n' % self.host_project_base
                    out.write(line)

        # make a script that sets the environment variables and calls Python.
        # Don't do this in bin/activate, because it's a pain to set/unset
        # properly (and for csh, fish as well).

        # Note that env_exe hasn't actually been created yet.

        sysconfig_name = os.path.basename(self.host_sysconfigdata_file)

upgrade=False,
                with_pip=False)
        env.create(context.cross_env_dir)
        context.cross_bin_path = os.path.join(context.cross_env_dir, 'bin')
        context.cross_env_exe = os.path.join(
                context.cross_bin_path, context.python_exe)
        context.cross_cfg_path = os.path.join(context.cross_env_dir, 'pyvenv.cfg')
        context.cross_activate = os.path.join(context.cross_bin_path, 'activate')

        # Remove binaries. We'll run from elsewhere
        for exe in os.listdir(context.cross_bin_path):
            if not exe.startswith('activate'):
                utils.remove_path(os.path.join(context.cross_bin_path, exe))

        # Alter pyvenv.cfg
        with utils.overwrite_file(context.cross_cfg_path) as out:
            with open(context.cross_cfg_path) as inp:
                for line in inp:
                    if line.split()[0:2] == ['home', '=']:
                        line = 'home = %s\n' % self.host_project_base
                    out.write(line)

        # make a script that sets the environment variables and calls Python.
        # Don't do this in bin/activate, because it's a pain to set/unset
        # properly (and for csh, fish as well).

        # Note that env_exe hasn't actually been created yet.

        sysconfig_name = os.path.basename(self.host_sysconfigdata_file)
        sysconfig_name, _ = os.path.splitext(sysconfig_name)

        # If this venv is generated from a cross-python still in its

libs = ''
                inc = ''

            libs = glob.glob(libs)
            if not libs:
                logger.warning("No libs in sysroot. Does it exist?")
            else:
                libs = os.pathsep.join(libs)
                extra_envs.append(('LIBRARY_PATH', ':=', libs))

            if not os.path.isdir(inc):
                logger.warning("No include/ in sysroot. Does it exist?")
            else:
                extra_envs.append(('CPATH', ':=', inc))

        utils.install_script('pywrapper.py.tmpl', context.cross_env_exe, locals())

        for exe in ('python', 'python3'):
            exe = os.path.join(context.cross_bin_path, exe)
            if not os.path.exists(exe):
                utils.symlink(context.python_exe, exe)

        # Install patches to environment
        utils.install_script('site.py.tmpl',
                os.path.join(context.lib_path, 'site.py'),
                locals())
        self.copy_and_patch_sysconfigdata(context)

        # cross-python is ready. We will use build-pip to install cross-pip
        # because 'python -m ensurepip' is likely to get confused and think
        # that there's nothing to do.
        if self.with_cross_pip:

logger.warning("No libs in sysroot. Does it exist?")
            else:
                libs = os.pathsep.join(libs)
                extra_envs.append(('LIBRARY_PATH', ':=', libs))

            if not os.path.isdir(inc):
                logger.warning("No include/ in sysroot. Does it exist?")
            else:
                extra_envs.append(('CPATH', ':=', inc))

        utils.install_script('pywrapper.py.tmpl', context.cross_env_exe, locals())

        for exe in ('python', 'python3'):
            exe = os.path.join(context.cross_bin_path, exe)
            if not os.path.exists(exe):
                utils.symlink(context.python_exe, exe)

        # Install patches to environment
        utils.install_script('site.py.tmpl',
                os.path.join(context.lib_path, 'site.py'),
                locals())
        self.copy_and_patch_sysconfigdata(context)

        # cross-python is ready. We will use build-pip to install cross-pip
        # because 'python -m ensurepip' is likely to get confused and think
        # that there's nothing to do.
        if self.with_cross_pip:
            logger.info("Installing cross-pip")

            # Make sure we install the same version of pip and setuptools to
            logger.debug("Installing: %s", context.build_pip_reqs)
            subprocess.check_output([context.cross_env_exe, '-m', 'pip',

def post_setup(self, context):
        """
        Extra processing. Put scripts/binaries in the right place.
        """

        utils.install_script('cross-expose.py.tmpl',
                os.path.join(context.bin_path, 'cross-expose'),
                locals())

        # Don't trust these to be symlinks. A symlink to Python will mess up
        # the virtualenv.

        # Add cross-python alias to the path. This is just for
        # convenience and clarity.
        for exe in os.listdir(context.cross_bin_path):
            target = os.path.join(context.cross_bin_path, exe)
            if not os.path.isfile(target) or not os.access(target, os.X_OK):
                continue
            dest = os.path.join(context.bin_path, 'cross-' + exe)
            utils.make_launcher(target, dest)

        # Add build-python and build-pip to the path.

utils.install_script('cross-expose.py.tmpl',
                os.path.join(context.bin_path, 'cross-expose'),
                locals())

        # Don't trust these to be symlinks. A symlink to Python will mess up
        # the virtualenv.

        # Add cross-python alias to the path. This is just for
        # convenience and clarity.
        for exe in os.listdir(context.cross_bin_path):
            target = os.path.join(context.cross_bin_path, exe)
            if not os.path.isfile(target) or not os.access(target, os.X_OK):
                continue
            dest = os.path.join(context.bin_path, 'cross-' + exe)
            utils.make_launcher(target, dest)

        # Add build-python and build-pip to the path.
        for exe in os.listdir(context.build_bin_path):
            target = os.path.join(context.build_bin_path, exe)
            if not os.path.isfile(target) or not os.access(target, os.X_OK):
                continue
            dest = os.path.join(context.bin_path, 'build-' + exe)
            utils.make_launcher(target, dest)

        logger.info("Finishing up...")
        activate = os.path.join(context.bin_path, 'activate')
        with open(activate, 'w') as fp:
            fp.write(dedent(F('''\
                . %(context.cross_activate)s
                export PATH=%(context.bin_path)s:$PATH
                ''', locals())))

"""

        # Directory structure:
        #
        # ENV_DIR/
        #   cross/      cross-python venv
        #   build/      build-python venv
        #   lib/        libs for setting up cross-python
        #   bin/        holds activate scripts.

        if os.path.exists(env_dir) and (self.clear_cross or self.clear_build):
            subdirs = os.listdir(env_dir)
            for sub in subdirs:
                if sub in ('cross', 'build'):
                    continue
                utils.remove_path(os.path.join(env_dir, sub))

        context = super().ensure_directories(env_dir)
        context.lib_path = os.path.join(env_dir, 'lib')
        context.exposed_libs = os.path.join(context.lib_path, 'exposed.txt')
        utils.mkdir_if_needed(context.lib_path)
        return context

sysname = sys.platform[0]
            machine = platform.machine()
        else:
            sysname = host_info[0]
            machine = host_info[-1]

        config['uname'] = {
            'sysname' : sysname.title(),
            'nodename' : 'build',
            'release' : '',
            'version' : '',
            'machine' : machine,
        }

        context.crossenv_cfg = os.path.join(context.env_dir, 'crossenv.cfg')
        with utils.overwrite_file(context.crossenv_cfg) as fp:
            config.write(fp)

extra_envs.append(('LIBRARY_PATH', ':=', libs))

            if not os.path.isdir(inc):
                logger.warning("No include/ in sysroot. Does it exist?")
            else:
                extra_envs.append(('CPATH', ':=', inc))

        utils.install_script('pywrapper.py.tmpl', context.cross_env_exe, locals())

        for exe in ('python', 'python3'):
            exe = os.path.join(context.cross_bin_path, exe)
            if not os.path.exists(exe):
                utils.symlink(context.python_exe, exe)

        # Install patches to environment
        utils.install_script('site.py.tmpl',
                os.path.join(context.lib_path, 'site.py'),
                locals())
        self.copy_and_patch_sysconfigdata(context)

        # cross-python is ready. We will use build-pip to install cross-pip
        # because 'python -m ensurepip' is likely to get confused and think
        # that there's nothing to do.
        if self.with_cross_pip:
            logger.info("Installing cross-pip")

            # Make sure we install the same version of pip and setuptools to
            logger.debug("Installing: %s", context.build_pip_reqs)
            subprocess.check_output([context.cross_env_exe, '-m', 'pip',
                '--disable-pip-version-check',
                'install',
                '--ignore-installed',

def F(s, values):
    values = FormatMapping(values)
    return s % values