debug: automatically Infer Path Mapping for Remote Debugging

[golang]

debug: automatically Infer Path Mapping for Remote Debugging

[koxu1996]

This is side comment that might help someone. Documentation regarding path mapping is not explaining clearly how to set it up and how it works. I had to investigate code and that allowed me to understand two things:

• remotePath keyword is misleading, because it's path to sources during executable build. Even if you move sources, then you must provide original one (I think they are compiled in), so for me name like originalBuildPath would be more clear.
• local path setup - this is actually path obtained from cwd, but I would prefer setting something like localPath explicitly.

[gopherbot]

Change https://golang.org/cl/234020 mentions this issue: Add logic to infer remote path automatically

[sbalabanov]

Does running ListPackagesBuildInfo involve discovering go packages, and thus running 'go list' on remote side? If so, getting this information can be pretty expensive.

In loaded IDE, we can know folders paths from opened project metadata, along with GOPATH and GOROOT. In 99.(9)% of the cases this is enough to match the remote file with the local one.

One concern that I have is that getting a list of all source paths from remote may be expensive.

[gopherbot]

Change https://golang.org/cl/236017 mentions this issue: src/debugAdapter/goDebug: add extra check for remote path inference

[hyangah]

BTW, is it possible for users to offer a delve configuration with explicit path mapping info currently?

[polinasok]

Yes, for now, but there is talk of taking out that option once this one is stable. The problem is that a single path option can only point to either user's source code or 3rd party library in a different directory, but not both.

[hyangah]

@polinasok Maybe my question was not specific. I am asking if users can supply config.yml that supports multiple path substitution.

[shaunco]

@koxu1996 - Thank you! I spent far too long trying to get breakpoints to work during a remote debug session between vscode on windows and delv in an ubuntu docker. Setting remotePath to the go workspace directory the binary was built from (even though it had no relation to the windows machine) and then setting cwd to ${workspaceFolder}, and everything worked.

It would be awesome if the vscode-go extension could just try remapping whatever paths are in the binary on the remote machine to the currently opened ${workspaceFolder}, as it seems like the most likely case.

https://github.com/golang/vscode-go/blob/master/docs/debugging.md#remote-debugging is also out of date and still mentions using program instead of cwd, among other things.

[gopherbot]

Change https://golang.org/cl/253741 mentions this issue: docs/debugging.md: update remote debugging documentation

[hyangah]

We updated the section for remote debugging. Please review and if you find it's still unclear and needs improvement, please file a new issue or submit your PRs.