NUnit sometimes ends with "unable to locate fixture"

Question

The NUnit-console 2.6.3 sometimes prints out the following error message instead of running tests. Here is excerpt from my Jenkins test build logs:

00:05:02.982 Process 'nunit-console-x86' [PID 3684] has begun profiling.
00:05:03.698 NUnit-Console version 2.6.3.13283
00:05:03.698 Copyright (C) 2002-2012 Charlie Poole.
00:05:03.698 Copyright (C) 2002-2004 James W. Newkirk, Michael C. Two, Alexei A. Vorontsov.
00:05:03.698 Copyright (C) 2000-2002 Philip Craig.
00:05:03.698 All Rights Reserved.
00:05:03.698 
00:05:03.698 Runtime Environment - 
00:05:03.701    OS Version: Microsoft Windows NT 6.1.7601 Service Pack 1
00:05:03.701   CLR Version: 2.0.50727.5485 ( Net 3.5 )
00:05:03.701 
00:05:03.795 ProcessModel: Default    DomainUsage: Single
00:05:03.795 Execution Runtime: net-3.5
00:05:33.886 Unable to locate fixture 
00:05:33.895 Process 'nunit-console-x86' [PID 3684] has finished profiling.

It happens randomly. I do not change the test assembly or the NUnit configuration. I run NUnit via NCover, but the same problem repeats when I use NUnit alone from the command line.

After enabling the verbose logging in NUnit I noticed that the nunit-agent process prints out its first messages to the log more than half a minute after it was run by the nunit-console. I found out from the source code that nunit-console waits 30 seconds for the spawned nunit-agent process to register itself. Apparently something delays loading nunit-agent so the timeout is hit in nunit-console causing the "Unable to locate fixture ". The nunit-agent process is still running after that and I have to kill it manually.

NUnit-console log:

InternalTrace: Initializing at level Verbose
09:14:08.992 Info  [ 1] Runner: NUnit-console.exe starting
09:14:09.006 Debug [ 1] ServiceManager: Added SettingsService
09:14:09.006 Debug [ 1] ServiceManager: Added DomainManager
09:14:09.007 Debug [ 1] ServiceManager: Added ProjectService
09:14:09.007 Debug [ 1] ServiceManager: Added AddinRegistry
09:14:09.007 Debug [ 1] ServiceManager: Added AddinManager
09:14:09.007 Debug [ 1] ServiceManager: Added TestAgency
09:14:09.008 Info  [ 1] ServiceManager: Initializing SettingsService
09:14:09.008 Info  [ 1] ServiceManager: Initializing DomainManager
09:14:09.008 Info  [ 1] ServiceManager: Initializing ProjectService
09:14:09.008 Info  [ 1] ServiceManager: Initializing AddinRegistry
09:14:09.008 Info  [ 1] ServiceManager: Initializing AddinManager
09:14:09.009 Debug [ 1] ServiceManager: Request for service IAddinRegistry satisfied by AddinRegistry
09:14:09.017 Info  [ 1] ServiceManager: Initializing TestAgency
09:14:09.041 Debug [ 1] ServiceManager: Request for service ProjectService satisfied by ProjectService
09:14:09.054 Debug [ 1] RuntimeFrameworkSelector: Current framework is net-3.5
09:14:09.054 Debug [ 1] RuntimeFrameworkSelector: No specific framework requested
09:14:09.054 Debug [ 1] ServiceManager: Request for service ISettings satisfied by SettingsService
09:14:09.058 Debug [ 1] RuntimeFrameworkSelector: Assembly D:\Jenkins\jobs\Job1\GreyBoxTests\bin\Debug\GreyBoxTests.dll uses version 4.0.30319
09:14:09.064 Debug [ 1] ServiceManager: Request for service TestAgency satisfied by TestAgency
09:14:09.065 Debug [ 1] RuntimeFrameworkSelector: Test will use net-4.0 framework
09:14:09.066 Info  [ 1] ProcessRunner: Loading GreyBoxTests.dll
09:14:09.067 Info  [ 1] TestAgency: Getting agent for use under net-4.0
09:14:09.070 Debug [ 1] TestAgency: Using nunit-agent at c:\Program Files (x86)\NUnit 2.6.3\bin\nunit-agent-x86.exe
09:14:09.091 Info  [ 1] TestAgency: Launched Agent process 7240 - see nunit-agent_7240.log
09:14:09.091 Info  [ 1] TestAgency: Command line: "c:\Program Files (x86)\NUnit 2.6.3\bin\nunit-agent-x86.exe" 65bc321d-e7dc-4a98-81e6-919b87d5c783 tcp://127.0.0.1:56614/TestAgency
09:14:09.091 Debug [ 1] TestAgency: Waiting for agent {65bc321d-e7dc-4a98-81e6-919b87d5c783} to register
09:14:39.091 Info  [ 1] Runner: NUnit-console.exe terminating

NUnit-agent log:

InternalTrace: Initializing at level Verbose
09:14:41.859 Info  [ 1] NUnitTestAgent: Agent process 7240 starting
09:14:41.876 Info  [ 1] NUnitTestAgent: Running under version 4.0.30319.18444, Net 4.5
09:14:41.876 Info  [ 1] NUnitTestAgent: Adding Services
09:14:41.876 Debug [ 1] ServiceManager: Added SettingsService
09:14:41.877 Debug [ 1] ServiceManager: Added ProjectService
09:14:41.877 Debug [ 1] ServiceManager: Added DomainManager
09:14:41.877 Debug [ 1] ServiceManager: Added AddinRegistry
09:14:41.877 Debug [ 1] ServiceManager: Added AddinManager
09:14:41.877 Info  [ 1] NUnitTestAgent: Initializing Services
09:14:41.878 Info  [ 1] ServiceManager: Initializing SettingsService
09:14:41.878 Info  [ 1] ServiceManager: Initializing ProjectService
09:14:41.878 Info  [ 1] ServiceManager: Initializing DomainManager
09:14:41.878 Info  [ 1] ServiceManager: Initializing AddinRegistry
09:14:41.878 Info  [ 1] ServiceManager: Initializing AddinManager
09:14:41.879 Debug [ 1] ServiceManager: Request for service IAddinRegistry satisfied by AddinRegistry
09:14:41.906 Info  [ 1] NUnitTestAgent: Connecting to TestAgency at tcp://127.0.0.1:56614/TestAgency
09:14:41.907 Info  [ 1] NUnitTestAgent: Starting RemoteTestAgent
09:14:41.908 Info  [ 1] RemoteTestAgent: Agent starting

Any NUnit experts could help me with this?

Pleasing

The NUnit developers would be most equipped to answer this, though they aren't active on SO. They are, however, quite responsive on their discussion group. Try there if you don't get an answer here, and be sure to follow up here if they are able to help! – Moneymaking

Thanks Patrick, I will post my question there. – Pleasing

Here's the link to the associated post: groups.google.com/d/msg/nunit-discuss/g9xTtq1n75w/P39y2V7k4JMJ – Flip

Answer 1

Potential workaround, suggested by Charlie in that Google Groups thread:

One way to avoid this is to stop using the agent. Change the config file (nunit-console-x86.exe.config) to use the 4.0 CLR before the 2.0 CLR. Then the test will run in the same process and no agent will be created.

I have confirmed that adding <supportedRuntime version="v4.0.30319" /> inside <startup> in the nunit-console.exe.config file (or nunit-console-x86.exe.config), and removing <supportedRuntime version="v2.0.50727" (if present) does cause my tests to run without spawning an nunit-agent.exe process. I have not confirmed whether that fixes the error "unable to locate fixture" in my case, but the OP (krzysiek_w) did confirm it in the same thread:

I was not aware of the possibility to run tests in nunit-console without the nunit-agent. After setting the supported framework in the nunit-console config file, the tests execute without creating the separate process which completely fixes the problem.

As an additional note, the option /trace=Verbose can be passed to NUnit to get more info, as krzysiek_w did in that thread. For me, those logs are output to C:\Users\(myuser)\AppData\Local\NUnit\logs.

Cervantez