bazel_ros2_rules generates invalid BUILD.bazel when there's an underlay

[sloretz]

Currently when an existing local ROS 2 workspace is sourced, bazel_ros2_rules will generate a BUILD.bazel file with absolute paths in places where Bazel labels are expected, thus making the whole build file invalid.

ros2_example_bazel_installed$ bazel build //...
Starting local Bazel server and connecting to it...
ERROR: Traceback (most recent call last):
    File "/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/BUILD.bazel", line 483, column 16, in <toplevel>
        share_filegroup(
    File "/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/tools/common.bzl", line 8, column 45, in share_filegroup
        srcs = [path for path in native.glob(
Error in glob: pattern cannot be absolute
ERROR: /home/sloretz/ws/drake-ros/drake-ros/ros2_example_bazel_installed/ros2_example_common/BUILD.bazel:6:24: no such target '@ros2//:action_msgs_defs': target 'action_msgs_defs' not declared in package '' defined by /home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/BUILD.bazel and referenced by '//ros2_example_common:_ros2_example_common_msgs__rosidl_typesupport_cpp_gen'
ERROR: /home/sloretz/ws/drake-ros/drake-ros/ros2_example_bazel_installed/ros2_example_common/BUILD.bazel:6:24: no such target '@ros2//:builtin_interfaces_defs': target 'builtin_interfaces_defs' not declared in package '' defined by /home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/BUILD.bazel and referenced by '//ros2_example_common:_ros2_example_common_msgs__rosidl_typesupport_cpp_gen'
ERROR: /home/sloretz/ws/drake-ros/drake-ros/ros2_example_bazel_installed/ros2_example_common/BUILD.bazel:6:24: every rule of type rosidl_generate_genrule implicitly depends upon the target '@ros2//:rosidl', but this target could not be found because of: no such target '@ros2//:rosidl': target 'rosidl' not declared in package '' defined by /home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/BUILD.bazel
ERROR: Analysis of target '//ros2_example_common:_ros2_example_common_msgs__rosidl_typesupport_cpp_gen' failed; build aborted: Analysis failed

Examples in BUILD.bazel

```Python share_filegroup( name = "rti_connext_dds_cmake_module_share", share_directories = ["/home/sloretz/ws/drake-ros/ros2/install/share/rti_connext_dds_cmake_module", "/home/sloretz/ws/drake-ros/ros2/install/share/ament_index"], ) ``` ```Python cc_library( name = "rmw_fastrtps_dynamic_cpp_cc", srcs = ["/home/sloretz/ws/drake-ros/ros2/install/lib/librmw_fastrtps_dynamic_cpp.so", "/home/sloretz/ws/drake-ros/ros2/install/lib/libfastrtps.so.2.6"], hdrs = glob(["{}/**/*.h*".format(x) for x in ["archive/rmw_fastrtps_dynamic_cpp"]]), includes = ["archive"], copts = ["-isystem /home/sloretz/ws/drake-ros/ros2/install/include/rmw_fastrtps_dynamic_cpp"], defines = [], linkopts = ["-Wl,-rpath,/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_cpp/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_c/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rcpputils/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rcutils/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rmw/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rmw_dds_common/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rmw_fastrtps_shared_cpp/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_runtime_c/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_fastrtps_c/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_fastrtps_cpp/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_introspection_c/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/rosidl_typesupport_introspection_cpp/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/fastcdr/lib:/home/sloretz/ws/drake-ros/ros2/install/lib:/home/sloretz/.cache/bazel/_bazel_sloretz/effac4167a518523c467e34b5d8c3dd7/external/ros2/archive/fastrtps/lib"], data = [":rmw_fastrtps_dynamic_cpp_share", "/home/sloretz/ws/drake-ros/ros2/install/lib/librmw_fastrtps_dynamic_cpp.so", "/home/sloretz/ws/drake-ros/ros2/install/lib/libfastrtps.so.2.6"], deps = [":rmw_dds_common_cc", ":rcutils_cc", ":rmw_fastrtps_shared_cpp_cc", ":rcpputils_cc", ":rosidl_runtime_c_cc", ":rosidl_typesupport_fastrtps_cpp_cc", ":rosidl_typesupport_introspection_c_cc", ":rosidl_typesupport_introspection_cpp_cc", ":rosidl_typesupport_fastrtps_c_cc", ":fastcdr_cc", ":fastrtps_cc", ":rmw_cc", ":fastrtps_cmake_module_cc"], ) ``` ```Python ros_import_binary( name = "ament_clang_format", executable = "/home/sloretz/ws/drake-ros/ros2/install/bin/ament_clang_format", data = [":action_msgs_cc", ":rclpy_cc", ":rcl_lifecycle_cc", ":rcl_lifecycle_transitive_py", ":builtin_interfaces_cc", ":tracetools_cc", ":rosidl_runtime_c_cc", ":rosidl_runtime_c_transitive_py", ":rclcpp_action_cc", ":rclcpp_action_transitive_py", ":rcl_interfaces_cc", ":unique_identifier_msgs_cc", ":rmw_cc", ":rmw_transitive_py", ":rcl_yaml_param_parser_cc", ":rosgraph_msgs_cc", ":rcutils_cc", ":rcl_cc", ":rcl_transitive_py", ":rosidl_default_generators_cc", ":rosidl_default_runtime_cc", ":rosidl_default_runtime_transitive_py", ":rmw_implementation_cc", ":rmw_implementation_transitive_py", ":rcpputils_cc", ":rcpputils_transitive_py", ":yaml_cc", ":rosidl_runtime_cpp_cc", ":rcl_logging_interface_cc", ":rcl_logging_interface_transitive_py", ":rosidl_typesupport_fastrtps_cpp_cc", ":rosidl_typesupport_introspection_cpp_cc", ":rmw_connextddsmicro_cc", ":ament_index_cpp_cc", ":rosidl_generator_c_cc", ":rosidl_typesupport_introspection_c_cc", ":rcl_action_cc", ":rcl_action_transitive_py", ":rosidl_typesupport_interface_cc", ":rosidl_generator_cpp_cc", ":rosidl_parser_cc", ":rcl_logging_noop_cc", ":rcl_logging_noop_transitive_py", ":rosidl_typesupport_fastrtps_c_cc", ":rmw_fastrtps_dynamic_cpp_cc", ":rmw_fastrtps_dynamic_cpp_transitive_py", ":rosidl_typesupport_c_cc", ":rosidl_typesupport_cpp_cc", ":rmw_cyclonedds_cpp_cc", ":rmw_cyclonedds_cpp_transitive_py", ":fastcdr_cc", ":rosidl_generator_py_cc", ":rclcpp_cc", ":rclcpp_transitive_py", ":lifecycle_msgs_cc", ":rmw_fastrtps_cpp_cc", ":rmw_fastrtps_cpp_transitive_py", ":libyaml_vendor_cc", ":rmw_connextdds_cc", ":ament_cmake_cc", ":ament_cmake_transitive_py", ":rmw_implementation_cmake_cc", ":ament_cmake_core_cc", ":ament_cmake_export_targets_cc", ":rmw_connextdds_common_cc", ":rmw_connextdds_common_transitive_py", ":rcl_logging_spdlog_cc", ":rcl_logging_spdlog_transitive_py", ":rosidl_cmake_cc", ":ament_cmake_version_cc", ":libstatistics_collector_cc", ":libstatistics_collector_transitive_py", ":rti_connext_dds_cmake_module_cc", ":ament_cmake_export_interfaces_cc", ":ament_cmake_test_cc", ":rmw_fastrtps_shared_cpp_cc", ":rmw_fastrtps_shared_cpp_transitive_py", ":fastrtps_cmake_module_cc", ":std_msgs_cc", ":ament_cmake_export_link_flags_cc", ":statistics_msgs_cc", ":rmw_dds_common_cc", ":ament_cmake_export_libraries_cc", ":ament_cmake_python_cc", ":ament_cmake_export_dependencies_cc", ":ament_cmake_export_include_directories_cc", ":rosidl_adapter_cc", ":ament_cmake_libraries_cc", ":ament_cmake_export_definitions_cc", ":ament_cmake_gen_version_h_cc", ":spdlog_vendor_cc", ":fastrtps_cc", ":ament_cmake_target_dependencies_cc"], deps = [":action_msgs_py", ":rclpy_py", ":builtin_interfaces_py", ":rcl_interfaces_py", ":unique_identifier_msgs_py", ":rpyutils_py", ":rosgraph_msgs_py", ":rcutils_py", ":rosidl_typesupport_fastrtps_cpp_py", ":rosidl_typesupport_introspection_cpp_py", ":ament_index_python_py", ":rosidl_generator_c_py", ":rosidl_typesupport_introspection_c_py", ":rosidl_generator_cpp_py", ":rosidl_parser_py", ":rosidl_typesupport_fastrtps_c_py", ":rosidl_typesupport_c_py", ":rosidl_typesupport_cpp_py", ":rosidl_generator_py_py", ":lifecycle_msgs_py", ":rosidl_cmake_py", ":rosidl_cli_py", ":ament_cmake_test_py", ":std_msgs_py", ":statistics_msgs_py", ":rmw_dds_common_py", ":rosidl_adapter_py"], ) ```

[sloretz]

Possible fixes

• Invoke ros2_local_repository on the underlay workspace, and use those rules?
• Maybe we should filter out any underlay workspaces from environment variables?
• emit an error message if the ROS 2 workspace is already sourced?

[EricCousineau-TRI]

Maybe we should filter out any underlay workspaces from environment variables?

I think this makes the most sense.

Ideally, our Bazel rules should be as explicit as possible in source code, and not change behavior based on envrionment variables, esp. if the goal is to explicitly list the chain of workspaces / overlays. If a user wants to use a workspace, they should explicitly list in their WORKSPACE. If they really want to be at the behest of their environment variables, they can use tricks like Anzu's os.bzl to load in env vars.

What do you think?