It looks like the HDF5 package is having trouble on Trusty Tahr on Travis CI, but it works with Precise Pangolin.
I just started a package that depends on the HDF5.jl. I pushed my branch, enabled Travis CI, and it failed at the build step:
INFO: Building HDF5 /usr/bin/sudo: 1: /usr/bin/sudo: [[: not found ================================[ ERROR: HDF5 ]================================= LoadError: failed process: Process(`sudo apt-get install hdf5-tools`, ProcessExited(1))  while loading /home/travis/.julia/v0.6/HDF5/deps/build.jl, in expression starting on line 44
I took a look at some other packages that used the HDF5 package, and all of the ones that had clean builds were last built on Precise, so I added:
.travis.yml file, and this worked fine.
I notice that Travis CI only just started rolling out Trusty as a default yesterday.
Does anyone know why this is failing? Any further info?