ProGet fail to index symbol on a CPP DLL/PDB

I am trying to use symbol server with a package containing a DLL made with CPP (Visual studio 2012 compiler), and i cannot made it work. The compiled pdb shows the following info:

C:\Users\ggherardi>srctool.exe -r c:\Users\ggherardi\Sources\VDSMath\src\Debug\VDSMath.pdb
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fittingevaluator.cpp
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fitmanager.cpp
<other files>

C:\Users\ggherardi>pdbstr.exe -r -s:srcsrv -p:"c:\Users\ggherardi\Sources\VDSMath\src\Debug\VDSMath.pdb"
<no output>

When i try to debug a program that references that DLL as a NuGet packages hosted in Proget, the PDB seems correctly downloaded, VS tells that the DLL has symbols loaded from the symbol cache, but i cannot step in into functions of that DLL. If i try to inspect the downloaded PDB i get this output:

C:\Users\ggherardi>srctool.exe -r c:\Users\ggherardi\VS2012Symbols\VDSMath.pdb\AA8E72D1DDB34A438DBF76B027E6D9C81\VDSMath.pdb
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fittingevaluator.cpp
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fitmanager.cpp
<other files>

C:\Users\ggherardi>pdbstr.exe -r -s:srcsrv -p:"c:\Users\ggherardi\VS2012Symbols\VDSMath.pdb\AA8E72D1DDB34A438DBF76B027E6D9C81\VDSMath.pdb"
SRCSRV: ini ------------------------------------------------
VERSION=2
INDEXVERSION=2
VERCTRL=http
SRCSRV: variables ------------------------------------------
SRCSRVVERCTRL=http
PGSERVER=http://localhost:81/source-files
PGFEED=Default
PGPKGID=VDSMath
PGPKGVER=1.0.99-b000000
HTTP_EXTRACT_TARGET=%pgserver%/%pgfeed%/%pgpkgid%/%pgpkgver%/%var2%
SRCSRVTRG=%http_extract_target%
SRCSRVCMD=
SRCSRV: source files ---------------------------------------
SRCSRV: end ------------------------------------------------

The strange part is that that there are no source files defined in the "SRCSRV: source files" section. Despite this, i can download source files from ProGet by navigating to one of the "source-files" url, for example:

http://localhost:81/source-files/Default/VDSMath/1.0.99-b000000/fittingevaluator.cpp

I am using ProGet Version 3.0.3 (Build 1), and I have an enterprise license.

Product: ProGet
Version: 3.0.3

UPDATE

Taking the ProGet srcsrv steam as example , I've created a new file VDSMath.pdb.srcsrv with the following content:

SRCSRV: ini ------------------------------------------------
VERSION=2
INDEXVERSION=2
VERCTRL=http
SRCSRV: variables ------------------------------------------
SRCSRVVERCTRL=http
PGSERVER=http://localhost:81/source-files
PGFEED=Default
PGPKGID=VDSMath
PGPKGVER=1.0.99-b000000
HTTP_EXTRACT_TARGET=%pgserver%/%pgfeed%/%pgpkgid%/%pgpkgver%/%var2%
SRCSRVTRG=%http_extract_target%
SRCSRVCMD=
SRCSRV: source files ---------------------------------------
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fittingevaluator.cpp*fittingevaluator.cpp
c:\users\ggherardi\sources\vdsmath\src\vdsmath\fitmanager.cpp*fitmanager.cpp
<other files>
SRCSRV: end ------------------------------------------------

I've then replaced the srcsrv stream in the PDB downloaded from ProGet with the following command:

pdbstr.exe -w -s:srcsrv -p:"c:\Users\ggherardi\VS2012Symbols\VDSMath.pdb\AA8E72D1DDB34A438DBF76B027E6D9C81\VDSMath.pdb" -i:"c:\Users\ggherardi\VS2012Symbols\VDSMath.pdb\AA8E72D1DDB34A438DBF76B027E6D9C81\VDSMath.pdb.srcsrv"

With this updated PDB i can step in library methods during debug, so the problem seems related to the way ProGet enumerate the source files referenced in the PDB.

UPDATE & FIX

To investigate the problem I've decompiled ProGet. The following code is extracted from Inedo.ProGet.WebApplication.SimpleHandlers.SymbolServerHandler:

using (Stream stream = File.OpenRead(packagePath))
{
    var zipFile = new ZipFile(stream);
    var pdbEntry = zipFile.GetEntry(pdbPath);
    var nupkgSrcFiles = zipFile.Cast<ZipEntry>()
        .Where(e => e.Name.StartsWith("src/", StringComparison.OrdinalIgnoreCase))
        .Select(e => e.Name.Substring("src/".Length))
        .ToArray();
    using (var pdbStream = new SeekableStream(() => zipFile.GetInputStream(pdbEntry), pdbEntry.Size))
    {
        using (var pdbFile = new PdbFile(pdbStream, false, true))
        {
            var pdbSrcFiles = pdbFile.EnumerateStreams()
                .Where(s => s.StartsWith("/src/files/", StringComparison.OrdinalIgnoreCase))
                .Select(s => s.Substring("/src/files/".Length))
                .ToArray();
            foreach (string pdbSrcFile in pdbSrcFiles)
            {
                string nupkgSrcFile = nupkgSrcFiles.FirstOrDefault(x => pdbSrcFile.Replace('\\', '/').IndexOf(x, StringComparison.OrdinalIgnoreCase) >= 0);
                if (nupkgSrcFile != null)
                {
                    Console.WriteLine("{0}*{1}", pdbSrcFile, nupkgSrcFile.TrimStart(new[] { '/' }));
                }
            }
        }
    }
}

The problem is that for a CPP/PDB there are no stream whose name start with "/src/files/" and so no file are referenced in the resulting srcsrv stream. To resolve the issue ProGet should not try to parse the PDB but instead extract source using srctool.exe with a command like this:

C:\Users\ggherardi>srctool.exe -r c:\Users\ggherardi\Sources\VDSMath\src\Debug\VDSMath.pdb

I've tested it and this seems to produce the expected results on both CPP and C# DLLs

Thanks so much! This has been logged as PG-208, and we plan to fix in the upcoming maintnence release (3.0.4)