CMake linking against shared library on windows: error about not finding .lib file

I've got a library definition in CMake that builds a shared library out of a small set of files, and I've got it compiling just fine on both linux and windows.

However, I've also got ano开发者_开发问答ther library that links against the shared library and it works fine on linux, however, on windows I get a message along the lines or "error can't find Release/nnet.lib" during link-time. Is there something special I have to do to get this to link on windows?

Edit, example:

Main shared library (filenames changed to protect the innocent):

ADD_LIBRARY(nnet SHARED
  src/nnet/file_1.cc src/nnet/file_3.cc  
  src/nnet/file_2.cc src/nnet/file_4.cc)

And then I'm building a python module that links in the library:

# Build python module
ADD_LIBRARY            (other_lib SHARED ${CMAKE_SOURCE_DIR}/src/boost/boost_main.cc)
TARGET_LINK_LIBRARIES  (other_lib nnet   ${PYTHON_LIBRARIES})

The rest is just boilerplate (eg: changing module extension to .pyd on windows, finding python libraries/headers, etc) And then when building in VS 2008 I get:

fatal error LNK1181: cannot open input file 'Release\nnet.lib'

when building other_lib. Note no errors are thrown while building nnet.

Ah, my problem was I forgot to include a __declspec(dllexport) in suitable places when building the library (can you tell I don't do windows programming a lot?).