Missing header file message --- warning or error?

I’m new to compiling the firmware, and have been following the instructions from Build and install the latest firmware for your keyboard — Kaleidoscope documentation and have started with the unmodified firmware to check I can build and install that.

When I compile the sketch, I get the following output:

Sketch uses 26522 bytes (92%) of program storage space. Maximum is 28672 bytes.
Global variables use 1355 bytes (52%) of dynamic memory, leaving 1205 bytes for local variables. Maximum is 2560 bytes.

Invalid library found in /home/jcgs/.arduino15/packages/keyboardio/hardware/avr/1.99.5/libraries/Kaleidoscope-LEDControl: no headers files (.h) found in /home/jcgs/.arduino15/packages/keyboardio/hardware/avr/1.99.5/libraries/Kaleidoscope-LEDControl

So it looks like it has compiled it, despite the directory mentioned not having any header files in it (I’ve checked, and there’s just a README there). Is this an error or a warning? Or have I mangled my Arduino installation and need to reinstall? It seems to have produced something that it’s happy to upload to the keyboard.

The Kaleidoscope-LEDControl plugin is…special, and it’s not actually located in the Kaleidoscope-LEDControl directory in the same way that other plugins are. I can’t fully explain the message, because I don’t build the firmware with the Arduino IDE, which does things in a different way than the CLI does, but it’s not too surprising that you got a successful build but also an error message like that.