Commands to setup working environment before build and execute stage. This may include environment variable settings for compilers, tools, source paths, etc.
For Windows example
    set PATH=c:\SEGGER\j-link\bin;%PATH% 
    set PLATFORM_SRC_BASE=.\platform\src
    

For Unix/Linux example
    export PATH=/usr/local/open-ocd/bin:$PATH
    export PLATFORM_SRC_BASE=./platform/src