Correction on .travis.yml file.

.travis.yml

# .travis.yaml
#
# This file is part of NEST.
#
# Copyright (C) 2004 The NEST Initiative
#
# NEST is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# NEST is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with NEST.  If not, see <http://www.gnu.org/licenses/>.


# This is the Travis CI top-level script to setup and run the NEST
# build and test environment.

language: python
#cache:  pip
#cache: ccache

# Using the Sudo-enabled Ubuntu Bionic (18.04 LTS).
sudo: required
dist: bionic

env:
  global:
    - MAKEFLAGS="-j 2"
stages:
   - Staticcheck
   - MPI-Threading-GSL-Python
   - Python-Full-build-Clang7-OsX
   - ARM64

# list of build stages to run. Stages with the same name get run in parallel.

jobs:
  include:
    - stage: Staticcheck
      python: 3.6.10
      env: xTHREADING=0 xMPI=0 xSIONLIB=0 xGSL=0 xLIBNEUROSIM=0 xLTDL=0 xREADLINE=0 xLIBBOOST=0 xPYTHON=0 xMUSIC=0 xSTATIC_ANALYSIS=1 xRUN_BUILD_AND_TESTSUITE=0 CACHE_NAME=JOB   # only static code analysis
    - stage: MPI-Threading-GSL-Python
      python: 3.6.10
      env: xTHREADING=1 xMPI=1 xSIONLIB=0 xGSL=1 xLIBNEUROSIM=0 xLTDL=1 xREADLINE=1 xLIBBOOST=1 xPYTHON=1 xMUSIC=0 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB
    - stage: MPI-Threading-GSL-Python
      python: 3.6.10
      env: xTHREADING=0 xMPI=1 xSIONLIB=0 xGSL=0 xLIBNEUROSIM=0 xLTDL=1 xREADLINE=1 xLIBBOOST=1 xPYTHON=0 xMUSIC=0 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB   # only MPI
    - stage: MPI-Threading-GSL-Python
      python: 3.6.10
      env: xTHREADING=1 xMPI=0 xSIONLIB=0 xGSL=0 xLIBNEUROSIM=0 xLTDL=1 xREADLINE=1 xLIBBOOST=1 xPYTHON=0 xMUSIC=0 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB   # only threading
    - stage: MPI-Threading-GSL-Python
      python: 3.6.10
      env: xTHREADING=0 xMPI=0 xSIONLIB=0 xGSL=0 xLIBNEUROSIM=0 xLTDL=0 xREADLINE=0 xLIBBOOST=0 xPYTHON=1 xMUSIC=0 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB   # Only Python
    - stage: Python-Full-build-Clang7-OsX
      python: 3.6.10
      env: xTHREADING=1 xMPI=1 xSIONLIB=1 xGSL=1 xLIBNEUROSIM=1 xLTDL=1 xREADLINE=1 xLIBBOOST=1 xPYTHON=1 xMUSIC=1 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB   # full
    - stage: Python-Full-build-Clang7-OsX
      language: cpp
      python: 3.6.10
      env: MATRIX_EVAL="CC=clang-7 && CXX=clang++-7" xRUN_BUILD_AND_TESTSUITE=1
    - stage: Python-Full-build-Clang7-OsX
      os: osx
      osx_image: xcode12 # Python 3.8.3 running on macOS 10.15.5
      language: shell      # language 'python' results in errors on macOS
      cache: ccache
      env: xTHREADING=1 xMPI=0 xGSL=1 xLIBNEUROSIM=0 xLTDL=1 xREADLINE=1 xPYTHON=1 xMUSIC=0 xSTATIC_ANALYSIS=0 xRUN_BUILD_AND_TESTSUITE=1 CACHE_NAME=JOB   # Without MUSIC, MPI and Libneurosim
#https://docs.travis-ci.com/user/installing-dependencies#Installing-Packages-with-the-APT-Addon
addons:
   apt:
    sources:
     - *BASE_SOURCES
     - r-packages-bionic
     - ubuntu-toolchain-r-test
     - llvm-toolchain-bionic-9
    packages:
     - *BASE_PACKAGES
     - gcc-8
     - g++-8
     - clang-7
     - build-essential
     - cmake
     - libltdl-dev
     - libreadline6-dev
     - libncurses5-dev
     - libgsl0-dev
     - python3-all-dev
     - ipython3
     - pkg-config
     - openmpi-bin
     - libopenmpi-dev
     - libpcre3
     - libpcre3-dev
     - llvm-9-dev
     - jq
     - pep8
     - libboost-filesystem-dev
     - libboost-regex-dev
     - libboost-wave-dev
     - libboost-python-dev
     - libboost-program-options-dev
     - libboost-test-dev
     - python3-mpi4py
#cache:
#   directory:
#     - $HOME/.cache

before_install:
   - export SOURCEDIR=$PWD
   # select the right C++ compiler version (gcc8) -- note that update-alternatives is not available on MacOS
   - |
     if [ "$TRAVIS_OS_NAME" = "linux" ]; then
       ls -lh /usr/bin/g++*
       ls -lh /usr/bin/gcc*
       ls -lh /usr/bin/c++*
       sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-8 20
       sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 10
       sudo update-alternatives --auto g++
       sudo update-alternatives --list g++
       sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 20
       sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 10
       sudo update-alternatives --auto gcc
       sudo update-alternatives --list gcc
       sudo update-alternatives --list c++
       sudo update-alternatives --auto c++
       g++ --version
       /usr/bin/c++ --version
     fi
   - |
     if [ "$xRUN_BUILD_AND_TESTSUITE" = "1" ]; then
         echo "+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +"
         echo "+         P R E P A R E   N E S T   B U I L D   E N V I R O N M E N T         +"
         echo "+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +"
         echo ${MATRIX_EVAL}
         eval "${MATRIX_EVAL}"
         cp extras/install_csa-libneurosim.sh $HOME
         cp extras/install_music.sh $HOME
         cp extras/install_sionlib.sh $HOME
         cp extras/install_libboost.sh $HOME
         cd $HOME/build
         echo $PATH
         if [ MATRIX_EVAL="CC=clang-7 && CXX=clang++-7" ]; then
           pyenv install --list
           pyenv global 3.6.10
         fi
         if [ "$TRAVIS_OS_NAME" = "osx" ]; then
           brew --version
           brew update
           brew info python
           brew install ccache
           export PATH="/usr/local/opt/ccache/libexec:$PATH"
           export PATH="/usr/local/opt/python/libexec/bin:$PATH"  # To use homebrew's Python
           brew tap brewsci/science
           brew tap brewsci/bio
           brew install coreutils gsl open-mpi automake autoconf libtool
           brew unlink gcc
           brew install gcc@8
           brew link gcc@8
           find /usr/local/Cellar/ -name Python\.h
           find /usr/local/Cellar/ -name \*python\*dylib
         fi

         if [ "$TRAVIS_OS_NAME" != "osx" ]; then
           # Upgrade pip and setuptools
           pip install --upgrade pip setuptools
           pip install nose
         else
           # updating pip breaks on osx, must install man-page free nose
           wget https://arken.nmbu.no/~plesser/nose-1.3.7noman-py3-none-any.whl  
           pip install nose-1.3.7noman-py3-none-any.whl
         fi
         # Installing additional packages using pip as they only have
         # outdated versions in the Travis package whitelist.
         # terminaltables is required by parse_travis_log.py to create
         # the build summary.
         pip install cython scipy matplotlib terminaltables junitparser
         pip install numpy==1.16.5
         pip list
     fi

install:
   - |
     if [ "$xRUN_BUILD_AND_TESTSUITE" = "1" ]; then
         which cython
         cython --version
         which python
         python --version
         which pip
         pip list
         which nosetests
         nosetests --version
         nosetests --plugins
         which cmake
         cmake --version
         echo ${CC}
         echo ${CXX}
     fi
before_script:
   # Change directory back to the NEST source code directory.
   - cd $SOURCEDIR
   - chmod +x extras/travis_build.sh

script:
   - set -o pipefail
   - ./extras/travis_build.sh 2>&1 | tee travis_build.sh.log
   - |
     if [ "$xRUN_BUILD_AND_TESTSUITE" = "1" ]; then
        python extras/parse_travis_log.py travis_build.sh.log ;
     fi
before_deploy:
   - |
     if [ "$xRUN_BUILD_AND_TESTSUITE" = "1" ]; then
         cd $TRAVIS_BUILD_DIR/build
         tar -zcvf reports.tar.gz ./reports
         tar -zcvf docs.tar.gz $TRAVIS_BUILD_DIR/result/share/doc/nest/*.*
         mkdir -p $TRAVIS_BUILD_DIR/build/artefacts_upload
         mv docs.tar.gz $TRAVIS_BUILD_DIR/build/artefacts_upload
         mv reports.tar.gz $TRAVIS_BUILD_DIR/build/artefacts_upload
     fi
# S3 Deployment (Uploading the Travis CI build artefacts to Amazon S3).
deploy:
  provider: s3
  access_key_id:
    secure: $ARTIFACTS_KEY
  secret_access_key:
    secure: $ARTIFACTS_SECRET
  bucket: "nest-travis-artefacts"
  region: eu-central-1
  skip_cleanup: true
  on:
    repo: nest/nest-simulator
    branch: master
    condition: xRUN_BUILD_AND_TESTSUITE = 1
  local-dir: "$TRAVIS_BUILD_DIR/build/artefacts_upload"
  upload-dir: "$TRAVIS_REPO_SLUG/$TRAVIS_BUILD_NUMBER/$TRAVIS_JOB_NUMBER"
  acl: bucket_owner_full_control