I don't think the whiteboard interviews expect an executable at the end of the process. It's not a complete test, but a partial one: testing if you can come up with suitable algorithms within a reasonable time - and perhaps how you work/your process. None of which is dependent on any (software/IDE) tools
If you're asking them to design something rather than build something off a pre-existing design, you might like to know that they actually understand the principles of design, and aren't relying on a tool to pretend they do.
It is completely reasonable to rely on a text editor and the language interpreter. Hell, even the language documentation.
This could be an issue with really fancy IDE features, but there's a world of difference between a whiteboard and an IDE - namely, a text editor and an interpreter/compiler.