Debugging Tools for Windows: Symbol Proxy doesn't proxy

Question

I'm attempting to set up a symbol proxy using symproxy.dll from Debugging Tools for Windows. When I issue ".reload /f" from the debugger, none of the symbol files can be found. It looks like Symproxy isn't going out to the Microsoft Symbol Server to actually get the symbols. I see nothing in Wireshark, for example.

SYMPROXY.DLL is definitely being loaded -- I can see some entries in the Event Log, and http://my-server/symbols/status returns valid-looking information.

I've followed the instructions in the documentation as far as I can tell. Why won't symproxy go to Microsoft's site? What am I doing wrong? I need this to work, because the machine on which I'm debugging doesn't have external access.

The box on which symproxy is running has Internet access -- I regularly use it for debugging. The symbol path configured in the registry for symproxy looks correct. It doesn't have to go through a proxy to get to the Internet, and I've configured that in the registry as well.

When I use !sym noisy on the other box, it contacts symproxy, but simply says "file not found". It's like the symproxy is simply serving the content, rather than doing a lookaside to the MS symbol servers, like it's supposed to.

Answer 1

first, do you have the right symbol server setting: http://msdl.microsoft.com/download/symbols

second, does your proxy box have access to the internet? and it is set up to allow the symproxy access? Could it be that the symproxy is not being proxied itself (check symhttp.doc in your debugging tools directory).

I would try a few steps to debug the debugger - can you run windbg with a crash dump on the proxy box, if so you can copy the symbols manually to your debugger box. If not, you need to resolve the internet access.

Answer 2

Also try a simple .symfix c:\symbols. That sets up your search path to be the default symbol site. You can also check your search paths to see what they are setup to be.

Answer 3

You have a couple of options available to you:

1. Make sure you are going against Microsoft's symbol server by using the .symfix (or .symfix+) commands. The "+" version keeps all of your other symbol paths and simply appends the official MS symbol server to your list.
2. Try typing "!sym noisy" before your reload command. This will instruct WinDbg to show you exactly how it's resolving your symbols, as well as what errors it is encountering along the way (no PDB, can't reach remote server, etc.)

Answer 4

In the meantime, I've installed and configured Squid on the shared machine. This seems to work. I'd have preferred to use symproxy, but I just don't have time to dig into why it's not working.