"#warning" not always being shown in the Error List

Question

I use this to mark code I need to come back to:

#warning Do more stuff here

However, sometimes these warning don't show up in the Error List window after a build. I can see the warnings in the compiler output window, but only some of them make it into the Error List. If I have the code file open that has these warnings they are always shown. If I have the code file closed, they don't appear most of the time. Is there a setting I can change to adjust this behaviour and always show the warnings in the Error List?

Answer 1

Select the "Treat warnings as errors -> All" radiobutton in the Build tab of the project's properties.

Answer 2

The reason is that, even if a warning occurs, the compiler normally considers this source file to be ok. So in an incremental build, the source file isn't recompiled, and the warning isn't displayed.