why does an assembly in the BIN folder get referenced at runtime from another assembly even though it was not included in project (but remained in build folder)

Finally what caused us to go looking further afield was this info from Unity error in building things

At the time of the exception, the container was:


  Resolving CRMService,(none)
  Calling constructor CRMService(ILog logger, SmtpClient mail)
 -- Could not load type 'Microsoft.Practices.EnterpriseLibrary.Common.Configuration.Manageability.ConfigurationElementManageabilityProviderAttribute' from assembly 'Microsoft.Practices.EnterpriseLibrary.Common, Version=6.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

Anyway it turns out that in the local and source controlled directories there was an orphaned EntLib 5.0 file ( Microsoft.Practices.EnterpriseLibrary.Caching.Database.dll) that wasn't correctly deleted/removed from things in this project, and so was still being dropped everywhere, and so obviously was being used as the "local" (preferred, in the order of build/bindings) of the compiler, and for some reason (perhaps xrm.client uses entlib internally?) was interfering with the way things were working.

So we found the offending file, removed it from the source control folder and everyone is happy again!

So does anyone have any insights into how we could have discovered this without spending as much time as we did - process? tools? etc...

Thanks in advance.