I seem to have hit on a scenario where when I run mstest on an AnyCPU assembly which references an x64 assembly, I get a BadImageFormatException.
The issue occurs when an interface in x64Production.dll is implemented (even if unused) by the AnyCPUTestingx64Production.dll test assembly:
Unable to load the test container 'D:\AnyCPUTestingx64Production.dll'
or one of its dependencies. error details:
System.BadImageFormatException:
Could not load file or assembly 'x64Production, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.
*** Assembly Binder Log Entry (09/02/2012 @ 09:44:26) ***
The operation failed.
Bind result: hr = 0x8007000b. An attempt was made to load a program with an incorrect format.
Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\MSTest.exe
--- A detailed error log follows.
=== Pre-bind state information ===
LOG: User = David
LOG: DisplayName = x64Production, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
(Fully-specified)
LOG: Appbase = file:///D:/
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = MSTest.exe
Calling assembly : AnyCPUTestingx64Production, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\MSTest.exe.Config
LOG: Using host configuration file:
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///D:/x64Production.DLL.
LOG: Assembly download was successful. Attempting setup of file: D:\x64Production.dll
LOG: Entering run-from-source setup phase.
LOG: Assembly Name is: x64Production, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
ERR: Failed to complete setup of assembly (hr = 0x8007000b). Probing terminated.
Has anyone else ascertained whether or not this is simply unsupported in the VS2010 mstest?
I came here searching for the solution for a similar problem. Posting this answer just in case the solution I found helps someone else. This solved it for me in Visual Studio (2012):
Add New Item -> Test Settings Change the testsetting By default this is set to "Force test to run in 32 bit process"
From the menu: Test -> Test Settings -> Select Test Settings File -> Choose the test settings file you have created.
Now run the tests.