I fired up Sandcastle Help File Builder today to generate documentation for my solution, which has around a dozen projects in it. Since I only want to generate documentation for, and run Sandcastle after, a Release build (which excludes all my test projects), I selected "Release" at the top of the window, just like in VS. Sandcastle appropriately looks for the gen'd XML files in my \bin\release subfolders for each project. However, it errors out when it cannot find DLL's for my test projects. It apparently sees those projects in the solution file, but doesn't realize I don't have builds for them in Release. I tried de-selecting them in the "API Filter" property, but this doesn't change anything.
How can I get Sandcastle to ignore those projects?