Window Size Weirdness when Compiling Blender on macOS

Like I have said here before, I love building and compiling Blender myself on my iMac. However, there is one bit of weird behavior that happens, almost always when making 2.8, and usually when making 2.7.

Every time I open the self-compiled versions, the main window does not completely fill in the space allocated to it by the OS, as you can see here:

The way that I have found to get around this is to grab the lower left corner of the window to make it smaller, and maximize it again. After that, it works quite nicely:

However, when I close the app can go back in, it opens up in the prior wonky position, and I have to do the window resize-maximize dance once again the get it to appear normally again.

I do not have this issue on the precompiled versions available from the downloads page, and this tells me that there is a setting somewhere on my system causing this.

Has anyone else encountered this issue while compiling on macOS?

There is a report for this in the tracker:
https://developer.blender.org/T57069

The cause is unknown, and it may depend on the macOS version you are using. The buildbot uses the latest Xcode / macOS SDK version, which might also make a difference.