Yesterday, however, I spent hours on a bug that was not actually a bug. I finally figured out through experimentation that CONFIG_POSIX_MQUEUE was not yet supported by WSL (I was trying to use mq_open() for IPC). The code that I was writing compiled perfectly, but would not run on the WSL. It ran without issue on the RPi.

Is there a list of "Danger: don't waste your time on this!" unsupported system calls for the WSL that would hopfully keep me from needlessly burning several hours of development time?

I do see Microsoft's list of partial support (https://msdn.microsoft.com/en-us/commandline/wsl/release_notes), but that doesn't help much. It even implies that inotify worked much sooner that it actually did in practice.

We have lists like this for browser support of things like CSS3 and HTML5... does it exist for the WSL?