Database project not able to add domain user

I am trying to define a domain user (an IIS AppPool service account) with permissions to access a database. Visual Studio, running on a winXP machine that is a member of the domain, complains that it cannot find the user.

C:\projects\FCIS\trunk\FCIS.Database\Schema Objects\Security\Users\REG1_fcisservice.user.sql(4,1): Error TSD4001: [User] .REG1\fcisservice: Windows NT user or group 'REG1\fcisservice' not found. Check the name again. (SQL error = 15401)
C:\projects\FCIS\trunk\FCIS.Database\Schema Objects\Security\Users\REG1_fcisservice.user.sql(8,1): Error TSD4001: [User] .REG1\fcisservice: Windows NT user or group 'REG1\fcisservice' not found. Check the name again. (SQL error = 15401) Done building project " FCIS.Database.dbproj" -- FAILED.

How should I go about ensuring Visual Studio can build and deploy with the domain user?

Erm, just trying to see if my one cent works. Where is the database? The machine that the database resides has to recognise the user in the first place or that user has to be given minimum access rights to the machine. Try to use the management studio to add the user, you probably has much better chance (of telling whether the database recognise the domain user) to locate and find the domain user.

If you are asking about building solutions, you need to provide access to the source files and folders and whatever rights necessary.

Both local workstation and database server are domain members. The domain user can be added manually. But it seems to me that Visual Studio is missing something to recognise that such a user exists. Because of this it is preventing me from building the SQL deployment script that would otherwise work just fine.

Microsoft support has offered the answer: I had only added REG\fcisservice as a login user in the remote SQL Server. Visual Studio needs to have the same done in the local SQL Server where it deploys a validation database for comparison work.