Linux-based platforms requires a container image with the following softwares:

• GCC 5.2 or later
• CMake 3.1 or later
• Python 3.6
• pip
• OpenCV 2.4 or later

Currently it uses okapies/buildenv image for linux-x86_64 platform.

.travis.yml -> run-build.sh -> build.sh -> scripts/*.sh

1. run-build.sh just calls a platform's build.sh for running the actual build workflow
2. build.sh
   • For Linux-based platforms, the build workflow is executed in the container
     • build.sh runs a Docker container at startup before executing the workflow
     • All commands are run via docker_exec and docker_exec_script functions (defined in init-build-linux.sh)
     • You can access ${HOME} (/home/travis) directory from inside the container transparently because it maps /home/travis in the Travis environment to container's /home/travis
   • For macOS (OSX), the build workflow is executed on the Travis' VM
   • Install the prerequisites
   • Run a build
   • Run a test
3. Release and clean up

• /home/travis (= ${HOME})
  • /downloads (cache)
  • /build
    • /protobuf-<ver> (cache)
    • /mkl-dnn-<ver> (cache)
    • /<user>/<repo> (= ${TRAVIS_BUILD_DIR})
      • /menoh
      • /test
      • /cmake
      • CMakeLists.txt
      • ...
      • /build
        • /menoh
        • /test
        • ...

cache:
  directories:
    - ${HOME}/downloads
    - ${HOME}/build/protobuf-${PROTOBUF_VERSION}
    - ${HOME}/build/mkl-dnn-${MKLDNN_VERSION}