def check(projects):
    """Check the specified projects for Python 3 compatibility."""
    log = logging.getLogger('ciu')
    log.info('{0} top-level projects to check'.format(len(projects)))
    print('Finding and checking dependencies ...')
    blockers = dependencies.blockers(projects)

    print('')
    for line in message(blockers):
        print(line)

    print('')
    for line in pprint_blockers(blockers):
        print(' ', line)

    return len(blockers) == 0
Check the specified projects for Python 3 compatibility.