[CMake] How to make ctest not buffer its output?

[Hugo Heden]

Good day all,

I use ctest --build-and-test to do some stuff that takes a long time.
It seems that ctest buffers the output of its subcommands so that
nothing is written (to the "terminal") until at the end. This is a
little unconvenient -- as a human I feel more comfortable actually
seeing that "something is happening".

Is there a way I can force ctest to not buffer the output of
subcommands, but rather just flush it?

Best regards

Hugo Heden