In Bazel, a successful build should be a quiet build. While build failures
should, of course, print ample information to stderr to aide in troubleshooting,
any custom Bazel code you write should not output progress information to stdout
or stderr. Let Bazel be responsible for overall build progress reporting.
For genrule or bash-based targets, I’ll often implement this by capturing
all output to a log file and only printing the log file if the target fails.