Expose errors encountered by the setup script

colcon_core/package_identification/python.py

@@ -1,3 +1,4 @@
+# Copyright 2019 Rover RObotics
 # Copyright 2016-2019 Dirk Thomas
 # Licensed under the Apache License, Version 2.0
 
@@ -29,7 +30,11 @@ def identify(self, desc):  # noqa: D102
         if not setup_py.is_file():
             return
 
-        config = get_setup_result(setup_py)
+        try:
+            config = get_setup_result(setup_py)
+        except Exception as e:
+            logger.warning(e)
+            return
 
         if 'metadata' not in config:
             return
@@ -78,13 +83,19 @@ def get_setup_result(setup_py, env=None):
     )
     p.start()
     p.join()
-    if p.exitcode:
-        logger.warning("Python setup script '%s' terminated with exit code %d",
-                    setup_py, p.exitcode)
 
     if not conn_recv.poll():
-        raise RuntimeError('No results available from Python setup script')
-    return conn_recv.recv()
+        raise RuntimeError('Python setup script "%s" did not return any data',
+                           setup_py)
+
+    result_or_error = conn_recv.recv()
+    conn_recv.close()
+
+    if isinstance(result_or_error, dict):
+        return result_or_error
+    else:
+        raise RuntimeError('Python setup script "%s" failed"',
+                           setup_py) from result_or_error
 
 
 def _get_setup_result_target(setup_py, env, conn_send):
@@ -95,35 +106,43 @@ def _get_setup_result_target(setup_py, env, conn_send):
 
     :param setup_py: path to a setup.py script
     :param env: environment variables to set before running setup.py
-    :param conn_send: Connection to send the results dictionary
+    :param conn_send: Connection to send the result as either a dict or
+                      an Exception.
     :return: None. Results are transmitted via conn_send.
     """
-    import os
-    import distutils.core
-
-    # need to be in setup.py's parent dir to detect any setup.cfg
-    os.chdir(os.path.dirname(setup_py))
-
-    # don't worry - the environments of functions called with
-    # subprocess.Process don't leak into each other
-    if env is not None:
-        os.environ.update(env)
-
-    result = distutils.core.run_setup(str(setup_py), stop_after='commandline')
-
-    # could just return all attrs in result.__dict__, but we take this
-    # opportunity to filter a few things that don't need to be there
-    conn_send.send({
-        attr: value for attr, value in result.__dict__.items()
-        if (
-            # These *seem* useful but always have the value 0.
-            # Look for their values in the 'metadata' object instead.
-            attr not in result.display_option_names
-            # Getter methods
-            and not callable(value)
-            # Private properties
-            and not attr.startswith('_')
-        )})
+    try:
+        import os
+        import distutils.core
+
+        # need to be in setup.py's parent dir to detect any setup.cfg
+        os.chdir(os.path.dirname(setup_py))
+
+        # don't worry - the environments of functions called with
+        # subprocess.Process don't leak into each other
+        if env is not None:
+            os.environ.update(env)
+
+            result = distutils.core.run_setup(
+                str(setup_py),
+                stop_after='commandline')
+
+        # could just return all attrs in result.__dict__, but we take this
+        # opportunity to filter a few things that don't need to be there
+        conn_send.send({
+            attr: value for attr, value in result.__dict__.items()
+            if (
+                # These *seem* useful but always have the value 0.
+                # Look for their values in the 'metadata' object instead.
+                attr not in result.display_option_names
+                # Getter methods
+                and not callable(value)
+                # Private properties
+                and not attr.startswith('_')
+            )})
+    except Exception as e:
+        conn_send.send(e)
+    finally:
+        conn_send.close()
 
 
 def create_dependency_descriptor(requirement_string):
@@ -141,8 +160,8 @@ def create_dependency_descriptor(requirement_string):
         '!=': 'version_neq',
         '<=': 'version_lte',
         '>=': 'version_gte',
-        '>': 'version_gt',
-        '<': 'version_lt',
+        '>':  'version_gt',
+        '<':  'version_lt',
     }
 
     requirement = parse_requirement(requirement_string)
@@ -156,7 +175,7 @@ def create_dependency_descriptor(requirement_string):
         else:
             logger.warn(
                 "Ignoring unknown symbol '{symbol}' in '{requirement}'"
-                .format_map(locals()))
+                    .format_map(locals()))
     return DependencyDescriptor(requirement.name, metadata=metadata)