ROS2之assert False, "Failed to find '// Generated: ' line"

使用colcon build编译turtlesim2，可能会出现如下错误：

需要修改，/opt/ros/dashing/lib/python3.6/site-packages/rosidl_typesupport_opensplice_cpp/__init__.py

使用如下代码进行替换，2019-08-05。

      # Copyright 2014-2018 Open Source Robotics Foundation, Inc.
      #
      # Licensed under the Apache License, Version 2.0 (the "License");
      # you may not use this file except in compliance with the License.
      # You may obtain a copy of the License at
      #
      # http://www.apache.org/licenses/LICENSE-2.0
      #
      # Unless required by applicable law or agreed to in writing, software
      # distributed under the License is distributed on an "AS IS" BASIS,
      # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      # See the License for the specific language governing permissions and
      # limitations under the License.
      import os
      import subprocess
      from rosidl_cmake import generate_files
      def generate_dds_opensplice_cpp(
       pkg_name, dds_interface_files, dds_interface_base_path, deps, output_basepath, idl_pp
      ):
       include_dirs = [dds_interface_base_path]
      for dep in deps:
      # only take the first : for separation, as Windows follows with a C:\
       dep_parts = dep.split(':', 1)
      assert len(dep_parts) == 2, "The dependency '%s' must contain a double colon" % dep
       idl_path = dep_parts[1]
       idl_base_path = os.path.dirname(
       os.path.dirname(os.path.dirname(os.path.normpath(idl_path))))
      if idl_base_path not in include_dirs:
       include_dirs.append(idl_base_path)
      if 'OSPL_TMPL_PATH' in os.environ:
       include_dirs.append(os.environ['OSPL_TMPL_PATH'])
      for idl_file in dds_interface_files:
      assert os.path.exists(idl_file), 'Could not find IDL file: ' + idl_file
      # get two level of parent folders for idl file
       folder = os.path.dirname(idl_file)
       parent_folder = os.path.dirname(folder)
       output_path = os.path.join(
       output_basepath,
       os.path.basename(parent_folder),
       os.path.basename(folder))
      try:
       os.makedirs(output_path)
      except FileExistsError:
      pass
      # idlpp doesn't like long path arguments over 256 chars, get just the filename
       filename = os.path.basename(idl_file)
       cmd = [idl_pp]
      for include_dir in include_dirs:
       cmd += ['-I', include_dir]
       cmd += [
      '-S',
      '-l', 'cpp',
      '-N',
      '-d', output_path,
      '-o', 'maintain-include-namespace',
       filename
       ]
      if os.name == 'nt':
       cmd[-1:-1] = [
      '-P',
      'ROSIDL_TYPESUPPORT_OPENSPLICE_CPP_PUBLIC_%s,%s' % (
       pkg_name,
      '%s/msg/rosidl_typesupport_opensplice_cpp__visibility_control.h' % pkg_name)]
       subprocess.check_call(cmd, cwd=folder)
      # modify generated code to
      # remove path information of the building machine as well as timestamps
       msg_name = os.path.splitext(filename)[0]
       idl_path = os.path.join(
       pkg_name, os.path.basename(parent_folder), filename)
       h_filename = os.path.join(output_path, '%s.h' % msg_name)
       _modify(h_filename, msg_name, _replace_path_and_timestamp, idl_path=idl_path)
       cpp_filename = os.path.join(output_path, '%s.cpp' % msg_name)
       _modify(cpp_filename, msg_name, _replace_path_and_timestamp, idl_path=idl_path)
       dcps_h_filename = os.path.join(output_path, '%sDcps.h' % msg_name)
       _modify(dcps_h_filename, msg_name, _replace_path_and_timestamp, idl_path=idl_path)
       dcps_cpp_filename = os.path.join(output_path, '%sDcps.cpp' % msg_name)
       _modify(dcps_cpp_filename, msg_name, _replace_path_and_timestamp, idl_path=idl_path)
      return 0
      def _modify(filename, msg_name, callback, idl_path=None):
      with open(filename, 'r') as h:
       lines = h.read().split('\n')
       modified = callback(lines, msg_name, idl_path=idl_path)
      if modified:
      with open(filename, 'w') as h:
       h.write('\n'.join(lines))
      def _replace_path_and_timestamp(lines, msg_name, idl_path):
       found_source = False
      for i, line in enumerate(lines):
      if line.startswith('// Source: '):
      assert not found_source, "More than one '// Source: ' line was found"
       found_source = True
       lines[i] = '// Source: ' + idl_path
      continue
      if line.startswith('// Generated: '):
      assert found_source, "No '// Source: ' line was found before"
       lines[i] = '// Generated: timestamp removed to make the build reproducible'
      break
      return lines
      def generate_typesupport_opensplice_cpp(arguments_file):
       mapping = {
      'idl__rosidl_typesupport_opensplice_cpp.hpp.em':  # noqa
      '%s__rosidl_typesupport_opensplice_cpp.hpp',
      'idl__dds_opensplice__type_support.cpp.em': 'dds_opensplice/%s__type_support.cpp',
       }
       generate_files(arguments_file, mapping)
  
 

https://github.com/ros2/rosidl_typesupport_opensplice/blob/master/rosidl_typesupport_opensplice_cpp/rosidl_typesupport_opensplice_cpp/__init__.py

具体原因分析参考：

1. https://github.com/ADLINK-IST/opensplice/issues/92

2. https://github.com/ros2/rosidl_typesupport_opensplice/pull/33

文章来源: zhangrelay.blog.csdn.net，作者：zhangrelay，版权归原作者所有，如需转载，请联系作者。

原文链接：zhangrelay.blog.csdn.net/article/details/98500543