Remote Development and Debugging with Visual Studio Code

Due to COVID-19, many of us are now working from home and are away from our dev machines. In my case, I know that I cannot work efficiently through a laggy VNC conneciton. While I could do most things through SSH and command line, debugging can be problematic.

A while ago I came across the Visual Studio Code Remote Development extension pack. This extension is new, so the documentation for it is not perfect, especially when your target machine is a Mac. I had a hard time finding solutions to the multiple problems I faced when setting this up, so I decided to write it up in a blog post.

Below are the steps needed for making VSC debugging work for a C++ project when on a Windows host connecting to a remote Mac. This even works when connecting to a remote VM! I imagine only slight modifications will be needed for other scenarios. The instructions assume you already have a C++ project setup for VSC on your remote machine.

Setting up Remote Development

• Locally, on your host, install VSC and the remote development extension .
• Open VSC, go to File → Preferences → Settings
  • Search for remote.SSH.showLoginTerminal. Enable this setting.
  • Search for remote.SSH.useLocalServer. Disable this setting.
• Now, press F1, search for and select the following: “Remote-SSH: Connect to Host…”
  • Enter <your_username>@<your_remote_machine_ip>
  • The VSC terminal will prompt for your VM’s password

After you enter your password you are connected to your VM and can browse/modify the files there as you would locally! The experience is much smoother than VNC or RDP.

Setting up Remote Debugging

To debug remotely, we will need a few more steps.

• While connected to your VM, we will need to install the following VSC extensions (this will install them on your VM and not your host):
  • C++ extension
  • CodeLLDB extension
• Turn on developer mode on your remote machine: $ sudo /usr/sbin/DevToolsSecurity --enable
• Add the following configuration to the .vscode/launch.json of your project:

{
  "name": "Launch (Remote)",
  "type": "lldb",
  "request": "launch",
  "program": "/path/to/your/program" // e.g. ${workspaceFolder}/a.out
}

• Go to the debugging tab of VSC, select the “Launch (Remote)” configuration, and F5 to debug!
• If you need to attach to a process, use the following configuration to .vscode/launch.json:

{
  "name": "Attach (Remote)",
  "type": "lldb",
  "request": "attach",
  "program": "/path/to/your/program", // e.g. ${workspaceFolder}/a.out
  "pid": "${command:pickProcess}"
}

• Using the “Attach (Remote)", after you press F5 a prompt will open where you can search for the process to attach to.

Hope you found this guide helpful. Happy debugging and stay safe out there!