NUnit isn't running Visual Studio 2010 code
Solution 1:
I've downloaded the NUnit 2.5 source and opened the VS2008 solution in the VS2010 beta. Once the conversion finished I opened all the projects and changed the target framework setting for all the projects to ".NET Framework 4.0". I then built the solution without any errors. I can now use the NUnit GUI app to run tests built for .NET 4.0. I've not done exhaustive testing of this build so there may be problems, but for my purposes it works fine.
Update: It is not necessary to rebuild NUnit. I discovered that if you add the following to the relevant NUnit config file you can run a test dll built for .NET 4.0.
Under <configuration> add:
<startup>
<supportedRuntime version="v4.0.30319" />
</startup>
and under <runtime> add:
<loadFromRemoteSources enabled="true" />
Solution 2:
With .NET 4 being released, I used
<supportedRuntime version="v4.0.30319" />
in the NUnit 2.5.4 exe.config instead of requiredRuntime, and the loadFromRemoteResources tag as shown above and all worked well. Thanks!
Solution 3:
You don't have to modify any file
just open this file and everything will work just fine
C:\Program Files (x86)\NUnit 2.5.10\bin\net-2.0\nunit-x86.exe
Solution 4:
In NUnit 2.5.5 you can specify in the command line the option /framework=net-4.0 and it is compatible with the new assemblies generated with the release of the latest VS2010.
Solution 5:
The proposed solution worked great for getting NUnit to run. Unfortunately, when I then got to my code coverage step, NCover started giving me:
Profiled process terminated. Profiler connection not established.
The best solution I found to this was to just use the "-x86" version of NUnit with NCover:
NCover.Console.exe nunit-console-x86.exe --additional params--
Works now.