[SOLVED] Headless debugging on Windows

Headless debugging on Windows

There is a bug that I would like to fix that only occurs on Windows Server without a GUI running. I have set up a Windows Server 2019 machine on Google Compute Engine that reproduces the bug, and would like to debug it.

Ideally, I would like to use gdb, but seeing as the program was built with Visual Studio 2019, gdb can't read the debugging symbols.

I don't have a Windows machine, so using Visual Studio will be difficult. I could set up a VM, but if there's an in-terminal way to do this that would be preferred.

I did a pretty thorough Google search, but it didn't turn up anything. Is there really no Windows solution for debugging C++ code headlessly?

Solution

MS has 2 console debuggers called CDB and NTSD so you don't actually need Visual Studio GUI to do the debugging. In fact there are a lot of debugging environments in Windows from MS beside the usual Visual Studio. Just install them in your Windows Server and control them remotely from your terminal

You can also debug MSVC-compiled code with LLDB since the PDB format has been published long time ago and LLVM on Windows does support it. No idea about current LLDB on Linux though

And since you have the source code, sometimes the old-school printf debugger is the best way to analyze the issue

If you can get a Windows VM it'll be much better to do remote debugging. In fact almost all debuggers support that feature including GDB or LLDB, so even if you don't have the source code you can still run any Windows debugger and step through the instructions instead of high-level code lines from a remote machine

An alternative way is to take a memory dump and debug later. After getting the dump file, just drag it into your VS solution or any debugging tool like WinDbg and then select "Start Debugging". Now you can step through instructions/code lines and examine variables' values, or jump to an arbitrary function's stack frame just as if you're really running the malfunctioning app

There are many ways to dump a process' memory. You can set Windows to automatically save a dump file when your app crashes, or just capture memory snapshots manually during runtime. Comparing 2 snapshots is also useful for detecting leaked memory. For more information on how to do that read

There's also an easy way to take a dump of a live process using task manager (or any other similar tools)