unittests and imported modules

[kdevel]

Today I moved some functions to a new module within the same 
package
and ran

    dmd -g -i -unittest -checkaction=context -main -run <filename>.

dmd reported

    5 unittests passed

I would have expected that only the one unittest in <filename> 
would
have been compiled. After inserting print statements into the
other modules I found that the additional four unittests originate
from the imported files. Is there a trick to get only the unittest
from <filename> run other than dropping the "-i" and specifiying
the other object files on the command line?

And why are the unittests from the imported phobos functions not 
run?