add explicit build flags management in pkgtest command
add explicit build flags management in pkgtest command


Former-commit-id: 6376fe84314af602ce77f5d41f6c2a2a26c99aa8 [formerly 457a6ddf814c7c8df95ceba3cd480aaad3c69081]
Former-commit-id: 008844f5e29731140c92b6f1fd2aeb684f0f3367
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine