Best practices with Nuget: Debug or Release?

Question

Currently, I package the release builds with Nuget for the official builds to nuget.org, but I package the debug builds with Nuget for the symbol source pushes to symbolsource.org.

EDIT: (Jon Skeet, with some bias from Noda Time development)

NuGet now supports pushing to both NuGet gallery and symbolsource.org (or similar servers), as documented. Unfortunately, there are two contradictory requirements here:

• When just using a library without any need for debugging, you really want a release build. That's what release builds are for, after all.
• When debugging into a library for diagnostic purposes, you really want a debug build with all the appropriate optimizations disabled. That's what debug builds are for, after all.

That would be fine, but NuGet doesn't (as far as I can tell) allow both the release and debug builds to be published in a useful way, in the same package.

So, the choices are:

• Distribute the debug builds to everyone (as shown in the example in the docs) and live with any size and performance hits.
• Distribute the release builds to everyone and live with a slightly impaired debug experience.
• Go for a really complicated distribution policy, potentially providing separate release and debug packages.

The first two really boil down to the effect of the differences between debug and release builds... although it's worth noting that there's also a big difference between wanting to step into the code of a library because you want to check some behaviour, and wanting to debug the code of a library because you believe you've found a bug. In the second case, it's probably better to get the code of the library as a Visual Studio solution and debug that way, so I'm not paying too much heed to that situation.

My temptation is to just keep with the release builds, with the expectation that relatively few people will need to debug, and the ones who do won't be impacted much by the optimizations in the release build. (The JIT compiler does most of the optimizing anyway.)

So, are there other options we hadn't considered? Are there other considerations which tip the balance? Is pushing NuGet packages to SymbolSource sufficiently new that "best practice" really hasn't been established?

Answer 1

Speaking for SymbolSource, I believe that the best practice is to:

1. Push release binary+content packages to nuget.org only (or any other production feed)
2. Push debug binary+content packages to a development feed:
   • on-premise
   • on myget.org
   • on nuget.org as pre-release packages.
3. Push both release and debug binary+symbols packages to symbolsource.org or any other symbol store.

While we're at it, it is a common misconception that release and debug builds in .NET really differ much, but I am assuming that the differentiation is here because of various code that might or might not be included in either build, like Debug.Asserts.

That said, it is really worth pushing both configurations to SymbolSource, because you just never know when you're going to need to debug production code. Remotely in production to make it harder. You're going to need the help you can get from your tooling when that happens. Which I obviously do not wish upon anyone.

There is still a matter to consider regarding versioning: is it correct to have 2 different packages (build in debug and in release) sharing 1 version number? SymbolSource would accept that, because it extracts packages and stores binaries in separate build mode branches, IF ONLY NuGet allowed to tag packages accordingly. There is no way at present to determine if a package is debug or release-mode.

Answer 2

I completely agree with your conclusion. NuGet packages with RELEASE and SymbolSource with debug. It seems pretty rare to step directly into packages and the occasional debug misstep with optimizations enabled might be acceptable.

If there were really a problem, I think the ideal solution would be to have NuGet support it. For example, imagine if when debugging, it could replace the release DLL with the one included in the SymbolSource package.

Ideally, what would happen then is that nuget pack SomePackage -Symbols against a release version would create a release nuget package, but a debug symbols package. And the VS plugin would be updated to be smart enough to see the association and pull in the Debug assemblies when running in a debugger and load those instead. Kind of crazy, but would be interesting.

However, I just don't see enough people complaining about this that it'd be worth it at the moment.

NuGet team accepts pull requests. :)

Answer 3

The example in the Creating and Publishing A Symbol Package references files in the Debug directories as sources for the dll and pdb files.

Specifying Symbol Package Contents

A symbol package can be built by conventions, from a folder structured in the way described in the previous section, or its contents can be specified using the files section. If you wanted to build the example package described previously, you could put this into your nuspec file:

<files>
  <file src="Full\bin\Debug\*.dll" target="lib\net40" /> 
  <file src="Full\bin\Debug\*.pdb" target="lib\net40" /> 
  <file src="Silverlight\bin\Debug\*.dll" target="lib\sl40" /> 
  <file src="Silverlight\bin\Debug\*.pdb" target="lib\sl40" /> 
  <file src="**\*.cs" target="src" />
</files>

Since the purpose of publishing the symbols is to allow others to step through your code when debugging, it seems most prudent to publish a version of the code intended for debugging without optimizations that might affect the code step through.