Described at https://github.com/travis-ci/travis-ci/issues/8826 there is a conflict between the gcc compiler and "oclint", which is a 'brew cask' that has been installed automatically before the mac builds start. This is one of the workarounds frequently suggested. The "|| true" anticipates that if 'oclint' were not installed, the removal command might signal failure; we actually want to just continue in this case, because it means upstream has fixed the bug.
Described at https://github.com/travis-ci/travis-ci/issues/8826 there is a conflict between the gcc compiler and "oclint", which is a 'brew cask' that has been installed automatically before the mac builds start. This is one of the workarounds frequently suggested. The "|| true" anticipates that if 'oclint' were not installed, the removal command might signal failure; we actually want to just continue in this case, because it means upstream has fixed the bug.