Mixed small stuff

If it happen frequently on the same test, we could modify this test to be more verbose or faster.

modify do_nightly_build_send to allow to specify where to get the files ...

Update check for non-available gradient.

Better error message when missing memory on the GPU.

Don't sum scan profile in the sum of printed profiles.

This duplicate the info as the outer func is already in the summed profile.

fix pickle cache leak

make apt-get more verbose to try to remove the 10 minutes without output...

Repair other tests following the merge of the new backend.

Small stuff

Reported by Caglar directly to me.