Modules with two leading slashes can't be mapped properly in debugger

[OEP]

I am finding the VS Code Python debugger doesn't understand paths with two leading slashes. These are valid paths on Linux which I think should be fine to debug, although in this case was introduced by accident.

Here is an example of a script to debug:

$ cat /tmp/vscode-path/vscode_blah.py 
import sys
import pprint
pprint.pprint(sys.path)

import debugpy
debugpy.listen(5678)
print("WAIT")
debugpy.wait_for_client()

print("HEY")

I set a breakpoint on that final "print".

What is strange is if I accidentally add two slashes at the beginning of my PYTHONPATH, the debugger can't properly path-map that.

# Does not work: "The editor could not be opened because the file was not found."
# (Creating the file tries to 'mkdir /vscode-path' and fails)
$ PYTHONPATH=//tmp/vscode-path python3 -c "import vscode_blah"

# Works great
$ PYTHONPATH=/tmp/vscode-path python3 -c "import vscode_blah"

Originally when I discovered this on a case I can't easily reproduce, I had a more descriptive error in the Call Stack pane of the debugger.

[UriError]: If a URI does not contain an authority component, then the path cannot begin with two slash characters ("//")

My debug configuration looks like this:

            {
                "host": "localhost",
                "name": "Remote Attach",
                "port": 5678,
                "request": "attach",
                "type": "python"
            }

I'm happy to convert this to a bug report, but wanted to check the pulse on this before.

[brettcannon]

Please open an issue at https://github.com/microsoft/debugpy .

[OEP]

Thanks, the issue is microsoft/debugpy#1061

[OEP]

debugpy says this is a VS Code issue microsoft/vscode#161498

[OEP]

I've come back around 😂 https://github.com/microsoft/vscode-python/issues/19874

[brettcannon]

The joys of abstractions and layers in software development. We will figure out where the code causing this exists eventually. 😅 Sorry about the run-around.

[OEP]

Ultimately this settled at microsoft/vscode#161498 but I think there are no changes being done to VS Code. I did find this workaround to remove the duplicate slashes though, in case others are having the same problem.

{
    "host": "localhost",
    "name": "Remote Attach",
    "port": 5678,
    "request": "attach",
    "type": "python",
    "pathMappings": [
        {
            "localRoot": "/",
            "remoteRoot": "//"
        }
    ],
}