The bazel build will output a lot of information when it compiles new things (cache miss situation) only in ninja builds, it seems we can add some flags to quiet this:

https://github.com/bazelbuild/bazel/issues/4867#issuecomment-830402410

--ui_event_filters=-info,-debug,-warning,-stderr,-stdout

The application of this flag should be tied to the VERBOSE value on the scons command line.

We may also want to prevent the bazel command from being printed on non VERBOSE build as its getting very large.