[MonoDevelop] Several projects in one solution - Assembly doesn't have an entry point

[Michael Gebhart]

Hi,

I have a monodevelop solution that contains two projects. The first
project is a library and the second is a program using the library. 

So in the options of the first project I choose "library" as target and
in the references of the second projects I added the first project.

The build process of the solution is successful, but when I try to run
the solution I get this error:

Assembly '/myProjectDirectory/bin/Debug/Practice.dll' doesn't have an
entry point.

When I compile everything manually with:

mcs -target:library Practice.cs (first project)
mcs -r:Practice.dll Test.cs (second project)

it works. Any ideas, what I am doing wrong?

Greetings

Mike