Travis CI MacOS builds with Fortran

Travis-CI MacOS builds (denoted osx in .travis.yml) emerged from beta in April 2013 using cloud-based Mac hardware. In January-March 2018, additional Travis-CI resources were progressively brought online, completed in March 2018. The speed for Travis-CI MacOS builds is quite fast, almost as fast to start as Linux.

Travis-CI MacOS queue

Template

Typical .travis.yml for MacOS (including Linux) for a Fortran build that happens to use Lapack and MPI looks like:

language: minimal
group: travis_latest

git:
  depth: 25
  quiet: true

env: FC=gfortran

addons:
  apt:
    packages: ['gfortran','liblapack-dev','libopenmpi-dev']

matrix:
  include:
  - os: linux
  - os: osx
    before_install:
    - brew upgrade gcc > /dev/null
    - brew install lapack open-mpi > /dev/null


install:
- cmake -B build
- cmake --build build

script:
- ctest --test-dir build --output-on-failure

Keep the brew update step as sometimes Travis-CI will break on brew install without first doing brew update if the Travis-CI MacOS image hasn’t been updated in a while.