ros2 galactic：Could not find ROS middleware implementation 'NOTFOUND'.

”╰+gǒが油メo ╬▍

@小鱼 docker用的是arm64的 Ubuntu20.04

小鱼

问题一定要描述清楚，终端打印一定复制粘贴，方便回答者检索和引用（你可以在linux系统上打开浏览器进社

复制粘贴下错误，我检索看看

”╰+gǒが油メo ╬▍

@小鱼 Starting >>> village_wang
--- stderr: village_wang
CMake Error at /opt/ros/galactic/share/rmw_implementation_cmake/cmake/get_default_rmw_implementation.cmake:60 (message):
Could not find ROS middleware implementation 'NOTFOUND'. Choose one of the
following:
Call Stack (most recent call first):
/opt/ros/galactic/share/rmw_implementation/cmake/rmw_implementation-extras.cmake:19 (get_default_rmw_implementation)
/opt/ros/galactic/share/rmw_implementation/cmake/rmw_implementationConfig.cmake:41 (include)
/opt/ros/galactic/share/rcl/cmake/ament_cmake_export_dependencies-extras.cmake:21 (find_package)
/opt/ros/galactic/share/rcl/cmake/rclConfig.cmake:41 (include)
/opt/ros/galactic/share/libstatistics_collector/cmake/ament_cmake_export_dependencies-extras.cmake:21 (find_package)
/opt/ros/galactic/share/libstatistics_collector/cmake/libstatistics_collectorConfig.cmake:41 (include)
/opt/ros/galactic/share/rclcpp/cmake/ament_cmake_export_dependencies-extras.cmake:21 (find_package)
/opt/ros/galactic/share/rclcpp/cmake/rclcppConfig.cmake:41 (include)
CMakeLists.txt:10 (find_package)

Failed <<< village_wang [26.0s, exited with code 1]

Summary: 0 packages finished [30.8s]
1 package failed: village_wang
1 package had stderr output: village_wang

小鱼

@2235674044 应该是galactic版本特有问题，请参考

”╰+gǒが油メo ╬▍

@小鱼我重新下载了一下ros2发现可以colcon build了但是run的时候出现了新的问题
root@90cfb8fcddd4:/home/town_ws# ros2 run village_wang wang2_node
1675329115.510342 [0] wang2_node: ddsi_udp_create_conn: set IP_MULTICAST_IF failed: Bad Parameter
[ERROR] [1675329115.546947863] [rmw_cyclonedds_cpp]: rmw_create_node: failed to create domain, error Error

[rcutils|error_handling.c:108] rcutils_set_error_state()
This error state is being overwritten:

'error not set, at /tmp/binarydeb/ros-galactic-rcl-3.1.4/src/rcl/node.c:261'

with this new error message:

'rcl node's rmw handle is invalid, at /tmp/binarydeb/ros-galactic-rcl-3.1.4/src/rcl/node.c:413'

rcutils_reset_error() should be called after error handling to avoid this.
<<<
[ERROR] [1675329115.557758259] [rcl]: Failed to fini publisher for node: 1
terminate called after throwing an instance of 'rclcpp::exceptions::RCLError'
what(): failed to initialize rcl node: rcl node's rmw handle is invalid, at /tmp/binarydeb/ros-galactic-rcl-3.1.4/src/rcl/node.c:413

小鱼

@2235674044 可以看下你怎么建立的docker吗

”╰+gǒが油メo ╬▍

@小鱼 docker安装：https://www.runoob.com/docker/ubuntu-docker-install.html 使用里面官方安装脚本自动安装的
容器创建：
1.安装qemu
2.docker run -itd --rm --net=none --platform linux/arm64 ubuntu:20.04 /bin/bash安装ubuntu20.04 arm64版本镜像并创建容器
3.容器打包成镜像
4.docker run -itd 打包镜像 /bin/bash

”╰+gǒが油メo ╬▍

@小鱼我发现好像没有这个文件
root@90cfb8fcddd4:/home/town_ws# cd /tmp/binarydeb/ros-galactic-rcl-3.1.4/src/rcl/
bash: cd: /tmp/binarydeb/ros-galactic-rcl-3.1.4/src/rcl/: No such file or directory
root@90cfb8fcddd4:/home/town_ws# cd /tmp/
root@90cfb8fcddd4:/tmp# ls
root@90cfb8fcddd4:/tmp# cd /
root@90cfb8fcddd4:/# find | grep ros-galactic-rcl-3.1.4
root@90cfb8fcddd4:/#
是不是这个问题，该怎么解决呢

小鱼

@2235674044 具体我也不是很清楚

@2235674044 在 ros2 galactic：Could not find ROS middleware implementation 'NOTFOUND'. 中说：

--net=none

把这个改成--net=host看看，另外输入下ip a
检查下本地的localhost是否正常

”╰+gǒが油メo ╬▍

@小鱼解决了，是qemu模拟环境问题，放到实际环境下就ok了

rty813

@小鱼实际上这个问题还是没有解决。我们的场景下确实有需求需要在qemu下使用ROS。这种情况下，还是会报错：ddsi_udp_create_conn: set IP_MULTICAST_IF failed: Bad Parameter。但是经过测试发现，仅cyclonedds会出现这种情况，而fastdds则没有问题。完整的报错如下：

1700209913.854902 [0]       main: selected interface "lo" is not multicast-capable: disabling multicast
1700209913.862237 [0]       main: ddsi_udp_create_conn: set IP_MULTICAST_IF failed: Bad Parameter
[ERROR] [1700209913.866479306] [rmw_cyclonedds_cpp]: rmw_create_node: failed to create domain, error Error

>>> [rcutils|error_handling.c:108] rcutils_set_error_state()
This error state is being overwritten:

  'error not set, at /opt/ros/foxy/src/ros2/rcl/rcl/src/rcl/node.c:276'

with this new error message:

  'rcl node's rmw handle is invalid, at /opt/ros/foxy/src/ros2/rcl/rcl/src/rcl/node.c:428'

rcutils_reset_error() should be called after error handling to avoid this.
<<<
[ERROR] [1700209913.873989803] [rcl]: Failed to fini publisher for node: 1

小鱼

@rty813 在 ros2 galactic：Could not find ROS middleware implementation 'NOTFOUND'. 中说：

1700209913.854902 [0] main: selected interface "lo" is not multicast-capable: disabling multicast
1700209913.862237 [0] main: ddsi_udp_create_conn: set IP_MULTICAST_IF failed: Bad Parameter

是没有解决，看提示估计因为只有一个 loopback ，且 lo 不支持多播，但关闭多播并没有传递到 ddsi_udp_create_conn 中，导致创建连接时在 lo 上依然启用多播造成失败，可以尝试手动启动 lo 的多播，指令如下
sudo ip link set lo multicast on

或者修改 cyclonedds 的代码修复，这个麻烦一些

rty813

@小鱼好像还是qemu的问题。我设置了Multicast on，但是依然报错。

我是在x86上运行的armv7的镜像，就会出现这种问题。如果运行的是x86镜像，就正常的。