ROS pub a topic,but cannot get info of topic by golang with goroslib

[liekkas99]

1、I try to get info of topic ,I write code by golang with goroslib，and start program in ubuntu18.04 as subcriber
2、I write a published with C++,and start program in ubuntu18.04 as published
subcriber get info as follow
[2022/04/27 16:19:46] [ERROR] subscriber '/ros_message' got an error: Client [/goroslib_sub] wants topic /ros_message to have datatype/md5sum [my_package/MessageDefine/bb2536dfe63ce438b01083e3738ff786], but our version has [my_package/MessageDefine/9a79d9978a17eda1bf6fd4440b27c26e]. Dropping connection.

I am c
ROS_C++.zip
onfused, what should I do? Please help me
golang_sub.zip
,

[liekkas99]

In order to keep the md5sum value the same between publisher(C++ Code) and subcriber(Golang Code)?
Now ,the fields in C++ message file can match fileds in Golang struct
But the error Always exist

[2022/04/27 16:19:46] [ERROR] subscriber '/ros_message' got an error: Client [/goroslib_sub] wants topic /ros_message to have datatype/md5sum [my_package/MessageDefine/bb2536dfe63ce438b01083e3738ff786], but our version has [my_package/MessageDefine/9a79d9978a17eda1bf6fd4440b27c26e]. Dropping connection.

[liekkas99]

Do is support ROS1.0 and melodic ?
that is my ROS version in ubunut18.04

[aler9]

You have to make sure that message definitions are the same on both the Go publisher and the C++ subscriber.

This library provides an utility that allows to convert C++ message definitions into Go definitions:

https://github.com/aler9/goroslib#import-existing-messages-services-and-actions

[ppbrown]

Hello,
I just found this issue.
I have a whole bunch of .msg files for a bunch of different topics and packages
Could you please give more details, in using the package-import tool, in the docs above?

I'm confused by the "--gopackage=/pkg/msgs" bit.
Is that always a literal hardcoded "/pkg/msgs", or is that really "/nameofyourpkg/msgs"..
Or is it "/filepath/to/your/pkg/msgs"? Or something else?

[aler9]

Hello, i checked the code and i found out that --gopackage and --rospackage are useless in case of package-import. I removed them and released a new version (v2.1.1).

[ppbrown]

one more related request.
The instructions dont mention where those utils like "package-import" get dropped. Apparently they get dropped in $HOME/go/bin, which is a general-purpose directory.
As such, how about renaming the utils to not be so generic?
"package-import" .. what package type?
Would be nicer named as "goroslib-package-import" or something