utils/build_externals.py

#!/usr/bin/python
#
# Please keep this code python 2.4 compatible and stand alone.

"""
Fetch, build and install external Python library dependancies.

This fetches external python libraries, builds them using your host's
python and installs them under our own autotest/site-packages/ directory.

Usage?  Just run it.
    utils/build_externals.py
"""

import compileall, logging, os, sha, shutil, sys, tempfile, time, urllib2
import subprocess, re
import common
from autotest_lib.client.common_lib import logging_config, logging_manager

# Where package source be fetched to relative to the top of the autotest tree.
PACKAGE_DIR = 'ExternalSource'

# Where packages will be installed to relative to the top of the autotest tree.
INSTALL_DIR = 'site-packages'

# Installs all packages, even if the system already has the version required
INSTALL_ALL = False


# Want to add more packages to fetch, build and install?  See the class
# definitions at the end of this file for examples of how to do it.


_READ_SIZE = 64*1024
_MAX_PACKAGE_SIZE = 100*1024*1024


class BuildExternalsLoggingConfig(logging_config.LoggingConfig):
    def configure_logging(self, results_dir=None, verbose=False):
        super(BuildExternalsLoggingConfig, self).configure_logging(
                                                               use_console=True,
                                                               verbose=verbose)

class Error(Exception):
    """Local exception to be raised by code in this file."""

class FetchError(Error):
    """Failed to fetch a package from any of its listed URLs."""


def main():
    """
    Find all ExternalPackage classes defined in this file and ask them to
    fetch, build and install themselves.
    """
    logging_manager.configure_logging(BuildExternalsLoggingConfig(),
                                      verbose=True)
    os.umask(022)

    top_of_tree = _find_top_of_autotest_tree()
    package_dir = os.path.join(top_of_tree, PACKAGE_DIR)
    install_dir = os.path.join(top_of_tree, INSTALL_DIR)

    # Make sure the install_dir is in our python module search path
    # as well as the PYTHONPATH being used by all our setup.py
    # install subprocesses.
    if install_dir not in sys.path:
        sys.path.insert(0, install_dir)
    env_python_path_varname = 'PYTHONPATH'
    env_python_path = os.environ.get(env_python_path_varname, '')
    if install_dir+':' not in env_python_path:
        os.environ[env_python_path_varname] = ':'.join([
            install_dir, env_python_path])

    fetched_packages, fetch_errors = fetch_necessary_packages(package_dir,
                                                              install_dir)
    install_errors = build_and_install_packages(fetched_packages, install_dir)

    # Byte compile the code after it has been installed in its final
    # location as .pyc files contain the path passed to compile_dir().
    # When printing exception tracebacks, python uses that path first to look
    # for the source code before checking the directory of the .pyc file.
    # Don't leave references to our temporary build dir in the files.
    logging.info('compiling .py files in %s to .pyc', install_dir)
    compileall.compile_dir(install_dir, quiet=True)

    # Some things install with whacky permissions, fix that.
    system("chmod -R a+rX '%s'" % install_dir)

    errors = fetch_errors + install_errors
    for error_msg in errors:
        print >>sys.stderr, error_msg

    return len(errors)


def fetch_necessary_packages(dest_dir, install_dir):
    """
    Fetches all ExternalPackages into dest_dir.

    @param dest_dir: Directory the packages should be fetched into.
    @param install_dir: Directory where packages will later installed.

    @returns A tuple containing two lists:
             * A list of ExternalPackage instances that were fetched and
               need to be installed.
             * A list of error messages for any failed fetches.
    """
    names_to_check = sys.argv[1:]
    errors = []
    fetched_packages = []
    for package_class in ExternalPackage.subclasses:
        package = package_class()
        if names_to_check and package.name.lower() not in names_to_check:
            continue
        if not package.is_needed(install_dir):
            logging.info('A new %s is not needed on this system.',
                         package.name)
            if INSTALL_ALL:
                logging.info('Installing anyways...')
            else:
                continue
        if not package.fetch(dest_dir):
            msg = '!!! Unable to download %s' % package.name
            print msg
            errors.append(msg)
        else:
            fetched_packages.append(package)

    return fetched_packages, errors


def build_and_install_packages(packages, install_dir):
    """
    Builds and installs all packages into install_dir.

    @param packages - A list of already fetched ExternalPackage instances.
    @param install_dir - Directory the packages should be installed into.

    @returns A list of error messages for any installs that failed.
    """
    errors = []
    for package in packages:
        if not package.build_and_install(install_dir):
            msg = '!!! Unable to build and install %s' % package.name
            print msg
            errors.append(msg)
    return errors


def _checksum_file(full_path):
    """@returns The hex checksum of a file given its pathname."""
    inputfile = open(full_path, 'rb')
    try:
        hex_sum = sha.sha(inputfile.read()).hexdigest()
    finally:
        inputfile.close()
    return hex_sum


def _find_top_of_autotest_tree():
    """@returns The full path to the top of the autotest directory tree."""
    dirname = os.path.dirname(__file__)
    autotest_dir = os.path.abspath(os.path.join(dirname, '..'))
    return autotest_dir


def system(commandline):
    """Same as os.system(commandline) but logs the command first."""
    logging.info(commandline)
    return os.system(commandline)


class ExternalPackage(object):
    """
    Defines an external package with URLs to fetch its sources from and
    a build_and_install() method to unpack it, build it and install it
    beneath our own autotest/site-packages directory.

    Base Class.  Subclass this to define packages.

    Attributes:
      @attribute urls - A tuple of URLs to try fetching the package from.
      @attribute local_filename - A local filename to use when saving the
              fetched package.
      @attribute hex_sum - The hex digest (currently SHA1) of this package
              to be used to verify its contents.
      @attribute module_name - The installed python module name to be used for
              for a version check.  Defaults to the lower case class name with
              the word Package stripped off.
      @attribute version - The desired minimum package version.
      @attribute os_requirements - A dictionary mapping a file pathname on the
              the OS distribution to a likely name of a package the user
              needs to install on their system in order to get this file.
      @attribute name - Read only, the printable name of the package.
      @attribute subclasses - This class attribute holds a list of all defined
              subclasses.  It is constructed dynamically using the metaclass.
    """
    subclasses = []
    urls = ()
    local_filename = None
    hex_sum = None
    module_name = None
    version = None
    os_requirements = None


    class __metaclass__(type):
        """Any time a subclass is defined, add it to our list."""
        def __init__(mcs, name, bases, dict):
            if name != 'ExternalPackage':
                mcs.subclasses.append(mcs)


    def __init__(self):
        self.verified_package = ''
        if not self.module_name:
            self.module_name = self.name.lower()
        self.installed_version = ''


    @property
    def name(self):
        """Return the class name with any trailing 'Package' stripped off."""
        class_name = self.__class__.__name__
        if class_name.endswith('Package'):
            return class_name[:-len('Package')]
        return class_name


    def is_needed(self, unused_install_dir):
        """@returns True if self.module_name needs to be built and installed."""
        if not self.module_name or not self.version:
            logging.warning('version and module_name required for '
                            'is_needed() check to work.')
            return True
        try:
            module = __import__(self.module_name)
        except ImportError, e:
            logging.info('Could not import %s.', self.module_name)
            return True
        self.installed_version = self._get_installed_version_from_module(module)
        logging.info('imported %s version %s.', self.module_name,
                     self.installed_version)
        return self.version > self.installed_version


    def _get_installed_version_from_module(self, module):
        """Ask our module its version string and return it or '' if unknown."""
        try:
            return module.__version__
        except AttributeError:
            logging.error('could not get version from %s', module)
            return ''


    def _build_and_install(self, install_dir):
        """Subclasses MUST provide their own implementation."""
        raise NotImplementedError


    def _build_and_install_current_dir(self, install_dir):
        """
        Subclasses that use _build_and_install_from_package() MUST provide
        their own implementation of this method.
        """
        raise NotImplementedError


    def build_and_install(self, install_dir):
        """
        Builds and installs the package.  It must have been fetched already.

        @param install_dir - The package installation directory.  If it does
            not exist it will be created.
        """
        if not self.verified_package:
            raise Error('Must call fetch() first.  - %s' % self.name)
        self._check_os_requirements()
        return self._build_and_install(install_dir)


    def _check_os_requirements(self):
        if not self.os_requirements:
            return
        failed = False
        for file_name, package_name in self.os_requirements.iteritems():
            if not os.path.exists(file_name):
                failed = True
                logging.error('File %s not found, %s needs it.',
                              file_name, self.name)
                logging.error('Perhaps you need to install something similar '
                              'to the %s package for OS first.', package_name)
        if failed:
            raise Error('Missing OS requirements for %s.  (see above)' %
                        self.name)


    def _build_and_install_current_dir_setup_py(self, install_dir):
        """For use as a _build_and_install_current_dir implementation."""
        egg_path = self._build_egg_using_setup_py(setup_py='setup.py')
        if not egg_path:
            return False
        return self._install_from_egg(install_dir, egg_path)


    def _build_and_install_current_dir_setupegg_py(self, install_dir):
        """For use as a _build_and_install_current_dir implementation."""
        egg_path = self._build_egg_using_setup_py(setup_py='setupegg.py')
        if not egg_path:
            return False
        return self._install_from_egg(install_dir, egg_path)


    def _build_and_install_current_dir_noegg(self, install_dir):
        if not self._build_using_setup_py():
            return False
        return self._install_using_setup_py_and_rsync(install_dir)


    def _build_and_install_from_package(self, install_dir):
        """
        This method may be used as a _build_and_install() implementation
        for subclasses if they implement _build_and_install_current_dir().

        Extracts the .tar.gz file, chdirs into the extracted directory
        (which is assumed to match the tar filename) and calls
        _build_and_isntall_current_dir from there.

        Afterwards the build (regardless of failure) extracted .tar.gz
        directory is cleaned up.

        @returns True on success, False otherwise.

        @raises OSError If the expected extraction directory does not exist.
        """
        self._extract_compressed_package()
        if self.verified_package.endswith('.tar.gz'):
            extension = '.tar.gz'
        elif self.verified_package.endswith('.tar.bz2'):
            extension = '.tar.bz2'
        elif self.verified_package.endswith('.zip'):
            extension = '.zip'
        else:
            raise Error('Unexpected package file extension on %s' %
                        self.verified_package)
        os.chdir(os.path.dirname(self.verified_package))
        os.chdir(self.local_filename[:-len(extension)])
        extracted_dir = os.getcwd()
        try:
            return self._build_and_install_current_dir(install_dir)
        finally:
            os.chdir(os.path.join(extracted_dir, '..'))
            shutil.rmtree(extracted_dir)


    def _extract_compressed_package(self):
        """Extract the fetched compressed .tar or .zip within its directory."""
        if not self.verified_package:
            raise Error('Package must have been fetched first.')
        os.chdir(os.path.dirname(self.verified_package))
        if self.verified_package.endswith('gz'):
            status = system("tar -xzf '%s'" % self.verified_package)
        elif self.verified_package.endswith('bz2'):
            status = system("tar -xjf '%s'" % self.verified_package)
        elif self.verified_package.endswith('zip'):
            status = system("unzip '%s'" % self.verified_package)
        else:
            raise Error('Unknown compression suffix on %s.' %
                        self.verified_package)
        if status:
            raise Error('tar failed with %s' % (status,))


    def _build_using_setup_py(self, setup_py='setup.py'):
        """
        Assuming the cwd is the extracted python package, execute a simple
        python setup.py build.

        @param setup_py - The name of the setup.py file to execute.

        @returns True on success, False otherwise.
        """
        if not os.path.exists(setup_py):
            raise Error('%sdoes not exist in %s' % (setup_py, os.getcwd()))
        status = system("'%s' %s build" % (sys.executable, setup_py))
        if status:
            logging.error('%s build failed.' % self.name)
            return False
        return True


    def _build_egg_using_setup_py(self, setup_py='setup.py'):
        """
        Assuming the cwd is the extracted python package, execute a simple
        python setup.py bdist_egg.

        @param setup_py - The name of the setup.py file to execute.

        @returns The relative path to the resulting egg file or '' on failure.
        """
        if not os.path.exists(setup_py):
            raise Error('%s does not exist in %s' % (setup_py, os.getcwd()))
        egg_subdir = 'dist'
        if os.path.isdir(egg_subdir):
            shutil.rmtree(egg_subdir)
        status = system("'%s' %s bdist_egg" % (sys.executable, setup_py))
        if status:
            logging.error('bdist_egg of setuptools failed.')
            return ''
        # I've never seen a bdist_egg lay multiple .egg files.
        for filename in os.listdir(egg_subdir):
            if filename.endswith('.egg'):
                return os.path.join(egg_subdir, filename)


    def _install_from_egg(self, install_dir, egg_path):
        """
        Install a module from an egg file by unzipping the necessary parts
        into install_dir.

        @param install_dir - The installation directory.
        @param egg_path - The pathname of the egg file.
        """
        status = system("unzip -q -o -d '%s' '%s'" % (install_dir, egg_path))
        if status:
            logging.error('unzip of %s failed', egg_path)
            return False
        egg_info = os.path.join(install_dir, 'EGG-INFO')
        if os.path.isdir(egg_info):
            shutil.rmtree(egg_info)
        return True


    def _install_using_setup_py_and_rsync(self, install_dir,
                                          setup_py='setup.py'):
        """
        Assuming the cwd is the extracted python package, execute a simple:

          python setup.py install --prefix=BLA

        BLA will be a temporary directory that everything installed will
        be picked out of and rsynced to the appropriate place under
        install_dir afterwards.

        Afterwards, it deconstructs the extra lib/pythonX.Y/site-packages/
        directory tree that setuptools created and moves all installed
        site-packages directly up into install_dir itself.

        @param install_dir the directory for the install to happen under.
        @param setup_py - The name of the setup.py file to execute.

        @returns True on success, False otherwise.
        """
        if not os.path.exists(setup_py):
            raise Error('%s does not exist in %s' % (setup_py, os.getcwd()))

        temp_dir = tempfile.mkdtemp(dir='/var/tmp')
        try:
            status = system("'%s' %s install --no-compile --prefix='%s'"
                            % (sys.executable, setup_py, temp_dir))
            if status:
                logging.error('%s install failed.' % self.name)
                return False

            # This makes assumptions about what python setup.py install
            # does when given a prefix.  Is this always correct?
            python_xy = 'python%s' % sys.version[:3]
            if os.path.isdir(os.path.join(temp_dir, 'lib')):
                # NOTE: This ignores anything outside of the lib/ dir that
                # was installed.
                temp_site_dir = os.path.join(
                        temp_dir, 'lib', python_xy, 'site-packages')
            else:
                temp_site_dir = temp_dir

            status = system("rsync -r '%s/' '%s/'" %
                            (temp_site_dir, install_dir))
            if status:
                logging.error('%s rsync to install_dir failed.' % self.name)
                return False
            return True
        finally:
            shutil.rmtree(temp_dir)



    def fetch(self, dest_dir):
        """
        Fetch the package from one its URLs and save it in dest_dir.

        If the the package already exists in dest_dir and the checksum
        matches this code will not fetch it again.

        Sets the 'verified_package' attribute with the destination pathname.

        @param dest_dir - The destination directory to save the local file.
            If it does not exist it will be created.

        @returns A boolean indicating if we the package is now in dest_dir.
        @raises FetchError - When something unexpected happens.
        """
        if not os.path.exists(dest_dir):
            os.makedirs(dest_dir)
        local_path = os.path.join(dest_dir, self.local_filename)

        # If the package exists, verify its checksum and be happy if it is good.
        if os.path.exists(local_path):
            actual_hex_sum = _checksum_file(local_path)
            if self.hex_sum == actual_hex_sum:
                logging.info('Good checksum for existing %s package.',
                             self.name)
                self.verified_package = local_path
                return True
            logging.warning('Bad checksum for existing %s package.  '
                            'Re-downloading', self.name)
            os.rename(local_path, local_path + '.wrong-checksum')

        # Download the package from one of its urls, rejecting any if the
        # checksum does not match.
        for url in self.urls:
            logging.info('Fetching %s', url)
            try:
                url_file = urllib2.urlopen(url)
            except (urllib2.URLError, EnvironmentError):
                logging.warning('Could not fetch %s package from %s.',
                                self.name, url)
                continue
            data_length = int(url_file.info().get('Content-Length',
                                                  _MAX_PACKAGE_SIZE))
            if data_length <= 0 or data_length > _MAX_PACKAGE_SIZE:
                raise FetchError('%s from %s fails Content-Length %d '
                                 'sanity check.' % (self.name, url,
                                                    data_length))
            checksum = sha.sha()
            total_read = 0
            output = open(local_path, 'wb')
            try:
                while total_read < data_length:
                    data = url_file.read(_READ_SIZE)
                    if not data:
                        break
                    output.write(data)
                    checksum.update(data)
                    total_read += len(data)
            finally:
                output.close()
            if self.hex_sum != checksum.hexdigest():
                logging.warning('Bad checksum for %s fetched from %s.',
                                self.name, url)
                os.unlink(local_path)
                continue
            logging.info('Good checksum.')
            self.verified_package = local_path
            return True
        else:
            return False


# NOTE: This class definition must come -before- all other ExternalPackage
# classes that need to use this version of setuptools so that is is inserted
# into the ExternalPackage.subclasses list before them.
class SetuptoolsPackage(ExternalPackage):
    # For all known setuptools releases a string compare works for the
    # version string.  Hopefully they never release a 0.10.  (Their own
    # version comparison code would break if they did.)
    version = '0.6c9'
    urls = ('http://pypi.python.org/packages/source/s/setuptools/'
            'setuptools-%s.tar.gz' % (version,),)
    local_filename = 'setuptools-%s.tar.gz' % version
    hex_sum = '79086433b341f0c1df45e10d586a7d3cc25089f1'

    SUDO_SLEEP_DELAY = 15


    def _build_and_install(self, install_dir):
        """Install setuptools on the system."""
        logging.info('NOTE: setuptools install does not use install_dir.')
        return self._build_and_install_from_package(install_dir)


    def _build_and_install_current_dir(self, install_dir):
        egg_path = self._build_egg_using_setup_py()
        if not egg_path:
            return False

        print '!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n'
        print 'About to run sudo to install setuptools', self.version
        print 'on your system for use by', sys.executable, '\n'
        print '!! ^C within', self.SUDO_SLEEP_DELAY, 'seconds to abort.\n'
        time.sleep(self.SUDO_SLEEP_DELAY)

        # Copy the egg to the local filesystem /var/tmp so that root can
        # access it properly (avoid NFS squashroot issues).
        temp_dir = tempfile.mkdtemp(dir='/var/tmp')
        try:
            shutil.copy(egg_path, temp_dir)
            egg_name = os.path.split(egg_path)[1]
            temp_egg = os.path.join(temp_dir, egg_name)
            p = subprocess.Popen(['sudo', '/bin/sh', temp_egg],
                                 stdout=subprocess.PIPE)
            regex = re.compile('Copying (.*?) to (.*?)\n')
            match = regex.search(p.communicate()[0])
            status = p.wait()

            if match:
                compiled = os.path.join(match.group(2), match.group(1))
                os.system("sudo chmod a+r '%s'" % compiled)
        finally:
            shutil.rmtree(temp_dir)

        if status:
            logging.error('install of setuptools from egg failed.')
            return False
        return True


class MySQLdbPackage(ExternalPackage):
    module_name = 'MySQLdb'
    version = '1.2.2'
    urls = ('http://downloads.sourceforge.net/project/mysql-python/'
            'mysql-python/%(version)s/MySQL-python-%(version)s.tar.gz'
            % dict(version=version),)
    local_filename = 'MySQL-python-%s.tar.gz' % version
    hex_sum = '945a04773f30091ad81743f9eb0329a3ee3de383'

    _build_and_install_current_dir = (
            ExternalPackage._build_and_install_current_dir_setup_py)


    def _build_and_install(self, install_dir):
        if not os.path.exists('/usr/bin/mysql_config'):
            logging.error('You need to install /usr/bin/mysql_config')
            logging.error('On Ubuntu or Debian based systems use this: '
                          'sudo apt-get install libmysqlclient15-dev')
            return False
        return self._build_and_install_from_package(install_dir)


class DjangoPackage(ExternalPackage):
    version = '1.0.2'
    local_filename = 'Django-%s-final.tar.gz' % version
    urls = ('http://media.djangoproject.com/releases/%s/%s'
            % (version, local_filename),)
    hex_sum = 'f2d9088f17aff47ea17e5767740cab67b2a73b6b'

    _build_and_install = ExternalPackage._build_and_install_from_package
    _build_and_install_current_dir = (
            ExternalPackage._build_and_install_current_dir_noegg)


    def _get_installed_version_from_module(self, module):
        try:
            return module.get_version().split()[0]
        except AttributeError:
            return '0.9.6'



class NumpyPackage(ExternalPackage):
    version = '1.2.1'
    local_filename = 'numpy-%s.tar.gz' % version
    urls = ('http://downloads.sourceforge.net/project/numpy/NumPy/%(version)s/'
            'numpy-%(version)s.tar.gz' % dict(version=version),)
    hex_sum = '1aa706e733aea18eaffa70d93c0105718acb66c5'

    _build_and_install = ExternalPackage._build_and_install_from_package
    _build_and_install_current_dir = (
            ExternalPackage._build_and_install_current_dir_setupegg_py)


# This requires numpy so it must be declared after numpy to guarantee that it
# is already installed.
class MatplotlibPackage(ExternalPackage):
    version = '0.98.5.3'
    short_version = '0.98.5'
    local_filename = 'matplotlib-%s.tar.gz' % version
    urls = ('http://downloads.sourceforge.net/project/matplotlib/matplotlib/'
            'matplotlib-%s/matplotlib-%s.tar.gz' % (short_version, version),)
    hex_sum = '2f6c894cf407192b3b60351bcc6468c0385d47b6'
    os_requirements = {'/usr/include/ft2build.h': 'libfreetype6-dev',
                       '/usr/include/png.h': 'libpng12-dev'}

    _build_and_install = ExternalPackage._build_and_install_from_package
    _build_and_install_current_dir = (
            ExternalPackage._build_and_install_current_dir_setupegg_py)


class AtForkPackage(ExternalPackage):
    version = '0.1.2'
    local_filename = 'atfork-%s.zip' % version
    urls = ('http://python-atfork.googlecode.com/files/' + local_filename,)
    hex_sum = '5baa64c73e966b57fa797040585c760c502dc70b'

    _build_and_install = ExternalPackage._build_and_install_from_package
    _build_and_install_current_dir = (
            ExternalPackage._build_and_install_current_dir_noegg)


class ParamikoPackage(ExternalPackage):
    version = '1.7.5'
    local_filename = 'paramiko-%s.tar.gz' % version
    urls = ('http://www.lag.net/paramiko/download/' + local_filename,)
    hex_sum = '592be7a08290070b71da63a8e6f28a803399e5c5'


    _build_and_install = ExternalPackage._build_and_install_from_package


    def _check_for_pycrypto(self):
        # NOTE(gps): Linux distros have better python-crypto packages than we
        # can easily get today via a wget due to the library's age and staleness
        # yet many security and behavior bugs are fixed by patches that distros
        # already apply.  PyCrypto has a new active maintainer in 2009.  Once a
        # new release is made (http://pycrypto.org/) we should add an installer.
        try:
            import Crypto
        except ImportError:
            logging.error('Please run "sudo apt-get install python-crypto" '
                          'or your Linux distro\'s equivalent.')
            return False
        return True


    def _build_and_install_current_dir(self, install_dir):
        if not self._check_for_pycrypto():
            return False
        # paramiko 1.7.4 doesn't require building, it is just a module directory
        # that we can rsync into place directly.
        if not os.path.isdir('paramiko'):
            raise Error('no paramiko directory in %s.' % os.getcwd())
        status = system("rsync -r 'paramiko' '%s/'" % install_dir)
        if status:
            logging.error('%s rsync to install_dir failed.' % self.name)
            return False
        return True


class GwtPackage(ExternalPackage):
    """Fetch and extract a local copy of GWT used to build the frontend."""

    version = '1.7.0'
    local_filename = 'gwt-linux-%s.tar.bz2' % version
    urls = ('http://google-web-toolkit.googlecode.com/files/' + local_filename,)
    hex_sum = 'accb39506e1fa719ba166cf54451c91dafd9d456'
    name = 'gwt'
    about_filename = 'about.txt'
    module_name = None  # Not a Python module.


    def is_needed(self, install_dir):
        gwt_dir = os.path.join(install_dir, self.name)
        about_file = os.path.join(install_dir, self.name, self.about_filename)

        if not os.path.exists(gwt_dir) or not os.path.exists(about_file):
            logging.info('gwt not installed for autotest')
            return True

        f = open(about_file, 'r')
        version_line = f.readline()
        f.close()

        match = re.match(r'Google Web Toolkit (.*)', version_line)
        if not match:
            logging.info('did not find gwt version')
            return True

        logging.info('found gwt version %s', match.group(1))
        return match.group(1) != self.version


    def build_and_install(self, install_dir):
        os.chdir(install_dir)
        self._extract_compressed_package()
        extracted_dir = self.local_filename[:-len('.tar.bz2')]
        target_dir = os.path.join(install_dir, self.name)
        if os.path.exists(target_dir):
            shutil.rmtree(target_dir)
        os.rename(extracted_dir, target_dir)
        return True


if __name__ == '__main__':
    sys.exit(main())