Output on failure on the build bots?

[mcourteaux]

From ctest --help:

  --output-on-failure          = Output anything outputted by the test
                                 program if the test should fail.

This would be very useful I think. Right now we are clueless as to what/why it failed.

[alexreinking]

We already capture the output ctest --output-on-failure

https://github.com/halide/build_bot/blob/22a4473a7c9113ca0b6f074f8292128d2976cc6f/master/custom_steps.py#L157-L171

Also see the code that blocks it into separate buildbot output streams here:

https://github.com/halide/build_bot/blob/22a4473a7c9113ca0b6f074f8292128d2976cc6f/master/custom_steps.py#L200-L207