Add ROS_PYTHON_VERSION to dependency conditionals. (#551)

* Raise rosdistro requirement to include new index-v4 changes.

The python_version key is required to supply ROS_PYTHON_VERSION to
conditional dependencies.

* Add API method for retrieving the distribution's python version.

* Add ROS_PYTHON_VERSION to conditional context.

* Fix pep8 conformance.

* Explicitly note when the python_version key is missing.

This feature will cause interruptions for bloom users whose version 4
rosdistro indexes lack this field. But I think this is preferred to a
silent or even vocal acceptance of a possibly invalid release state due
to missing conditional variables.

bloom/generators/common.py

@@ -42,6 +42,7 @@
 
 from bloom.rosdistro_api import get_distribution_type
 from bloom.rosdistro_api import get_index
+from bloom.rosdistro_api import get_python_version
 
 from bloom.util import code
 from bloom.util import maybe_continue
@@ -139,9 +140,24 @@ def package_conditional_context(ros_distro):
     else:
         error("Bloom cannot cope with distribution_type '{0}'".format(
             distribution_type), exit=True)
+    python_version = get_python_version(ros_distro)
+    if python_version is None:
+        error(
+            'No python_version found in the rosdistro index. '
+            'The rosdistro index must include this key for bloom to work correctly.',
+            exit=True)
+    elif python_version == 2:
+        ros_python_version = '2'
+    elif python_version == 3:
+        ros_python_version = '3'
+    else:
+        error("Bloom cannot cope with python_version '{0}'".format(
+            python_version), exit=True)
+
     return {
             'ROS_VERSION': ros_version,
             'ROS_DISTRO': ros_distro,
+            'ROS_PYTHON_VERSION': ros_python_version,
             }
 
 

bloom/rosdistro_api.py

@@ -137,6 +137,10 @@ def get_distribution_type(distro):
     return get_index().distributions[distro].get('distribution_type')
 
 
+def get_python_version(distro):
+    return get_index().distributions[distro].get('python_version')
+
+
 def get_most_recent(thing_name, repository, reference_distro):
     reference_distro_type = get_distribution_type(reference_distro)
     distros_with_entry = {}

setup.py

@@ -10,7 +10,7 @@
     'python-dateutil',
     'PyYAML',
     'rosdep >= 0.15.0',
-    'rosdistro >= 0.7.0',
+    'rosdistro >= 0.7.5',
     'vcstools >= 0.1.22',
 ]
 

stdeb.cfg

@@ -1,6 +1,6 @@
 [DEFAULT]
-Depends: python-yaml, python-empy, python-argparse, python-rosdep (>= 0.15.0), python-rosdistro (>= 0.7.0), python-vcstools (>= 0.1.22), python-setuptools, python-catkin-pkg (>= 0.4.3)
-Depends3: python3-yaml, python3-empy, python3-rosdep (>= 0.15.0), python3-rosdistro (>= 0.7.0), python3-vcstools (>= 0.1.22), python3-setuptools, python3-catkin-pkg (>= 0.4.3)
+Depends: python-yaml, python-empy, python-argparse, python-rosdep (>= 0.15.0), python-rosdistro (>= 0.7.5), python-vcstools (>= 0.1.22), python-setuptools, python-catkin-pkg (>= 0.4.3)
+Depends3: python3-yaml, python3-empy, python3-rosdep (>= 0.15.0), python3-rosdistro (>= 0.7.5), python3-vcstools (>= 0.1.22), python3-setuptools, python3-catkin-pkg (>= 0.4.3)
 Conflicts: python3-bloom
 Conflicts3: python-bloom
 Copyright-File: LICENSE.txt