fw/version: Introduce required version for devlib

To ensure that a compatible version of devlib is installed on the system
keep track of the version of devlib that is required by WA and provide a
more useful error message if this is not satisfied.

setup.py

@@ -29,7 +29,8 @@ except ImportError:
 wa_dir = os.path.join(os.path.dirname(__file__), 'wa')
 
 sys.path.insert(0, os.path.join(wa_dir, 'framework'))
-from version import get_wa_version, get_wa_version_with_commit
+from version import (get_wa_version, get_wa_version_with_commit,
+                     format_version, required_devlib_version)
 
 # happens if falling back to distutils
 warnings.filterwarnings('ignore', "Unknown distribution option: 'install_requires'")
@@ -83,7 +84,7 @@ params = dict(
         'colorama',  # Printing with colors
         'pyYAML',  # YAML-formatted agenda parsing
         'requests',  # Fetch assets over HTTP
-        'devlib>=1.1.dev1',  # Interacting with devices
+        'devlib>={}'.format(format_version(required_devlib_version)),  # Interacting with devices
         'louie-latest',  # callbacks dispatch
         'wrapt',  # better decorators
         'pandas>=0.23.0',  # Data analysis and manipulation
@@ -123,7 +124,6 @@ class sdist(orig_sdist):
         orig_sdist.initialize_options(self)
         self.strip_commit = False
 
-
     def run(self):
         if self.strip_commit:
             self.distribution.get_version = get_wa_version

wa/framework/entrypoint.py

@@ -21,14 +21,19 @@ import os
 import warnings
 
 import devlib
+try:
+    from devlib.utils.version import version as installed_devlib_version
+except ImportError:
+    installed_devlib_version = None
 
 from wa.framework import pluginloader
 from wa.framework.command import init_argument_parser
 from wa.framework.configuration import settings
 from wa.framework.configuration.execution import ConfigManager
 from wa.framework.host import init_user_directory, init_config
-from wa.framework.exception import ConfigError
-from wa.framework.version import get_wa_version_with_commit
+from wa.framework.exception import ConfigError, HostError
+from wa.framework.version import (get_wa_version_with_commit, format_version,
+                                  required_devlib_version)
 from wa.utils import log
 from wa.utils.doc import format_body
 
@@ -64,6 +69,13 @@ def split_joined_options(argv):
     return output
 
 
+# Instead of presenting an obscure error due to a version mismatch explicitly warn the user.
+def check_devlib_version():
+    if not installed_devlib_version or installed_devlib_version < required_devlib_version:
+        msg = 'WA requires Devlib version >={}. Please update the currently installed version {}'
+        raise HostError(msg.format(format_version(required_devlib_version), devlib.__version__))
+
+
 def main():
     if not os.path.exists(settings.user_directory):
         init_user_directory()
@@ -102,6 +114,7 @@ def main():
         logger.debug('Version: {}'.format(get_wa_version_with_commit()))
         logger.debug('devlib version: {}'.format(devlib.__full_version__))
         logger.debug('Command Line: {}'.format(' '.join(sys.argv)))
+        check_devlib_version()
 
         # each command will add its own subparser
         subparsers = parser.add_subparsers(dest='command')

wa/framework/version.py

@@ -23,13 +23,19 @@ VersionTuple = namedtuple('Version', ['major', 'minor', 'revision', 'dev'])
 
 version = VersionTuple(3, 1, 1, 'dev1')
 
+required_devlib_version = VersionTuple(1, 1, 0, 'dev1')
+
+
+def format_version(v):
+    version_string = '{}.{}.{}'.format(
+        v.major, v.minor, v.revision)
+    if v.dev:
+        version_string += '.{}'.format(v.dev)
+    return version_string
+
 
 def get_wa_version():
-    version_string = '{}.{}.{}'.format(
-        version.major, version.minor, version.revision)
-    if version.dev:
-        version_string += '.{}'.format(version.dev)
-    return version_string
+    return format_version(version)
 
 
 def get_wa_version_with_commit():