The install relies on brew. please see https://brew.sh, also we will be using default apps clang compiler. Alternatively we can use gnu, but this requires additional steps as we will need to build boost ourselves.
first install brew. Paste that in a macOS Terminal or Linux shell prompt.
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
next install ecflow dependencies
brew install boost brew install boost-python3 brew install openssl brew install qt
Download and place in $HOME/git
git clone ssh://git@git.ecmwf.int/ecflow/ecflow.git git clone ssh://git@git.ecmwf.int/ecsdk/ecbuild.git
build ecflow, and will install to ${HOME}/install/ecflow/${version}
cd $HOME/git/ecflow git checkout develop sh -x build_scripts/mac.sh make -j8 install # if you make a mistake use: sh -x build_scripts/mac.sh clean make -j8 install # clean will blast build directory