From version 1.13-pre2 onward, when the game is minimized the game output console gets spammed every frame (meaning upto hundreds of messages every second) with the following message:

[Client thread/INFO]: OpenGL debug message, id=1281, source=API, type=ERROR, severity=HIGH, message=GL_INVALID_VALUE error generated. View frustum must not have a zero values of: (right-left), (top-bottom), or (zFar-zNear).

This also creates log files that are huge in size, with the higher the framerate the game is running at the quicker the log file grows in size. Running at 240 fps the log file seems to increase about 1mb every 17 seconds. Meaning that running the game minimized at 240 fps for 5 hours would result in a log file of a gigabyte in size.

This occurs anywhere in the game, even on the main menu (where the splash text is and singleplayer and multiplayer buttons are).

Not sure if this is specific to some environments, but I'm on the following:
Windows 7 (64 bit)
Java 1.8.0_202-b08
GTX 970 with driver version 419.67.

Notes for myself ruling stuff that I've tried out:
-Not world specific
-Still occurs with 1 monitor
-Occurs in both fullscreen and windowed mode
-Not resource pack specific (happens without any resource packs loaded)