Plack has been removed.

Plack uses 'server_start' to spin up a web server and
that process does not respect SIGTERM. I am tired of
wrestling with this to get Plack working; if you want
Plack added back, make it behave and open a pull request.

toolset/benchmark/benchmarker.py

@@ -693,7 +693,7 @@ def exit_with_code(code):
  def __stop_test(self, out, process):
    if process is not None:
      # Kill the children
      subprocess.call(['pkill', '-P', process.pid], stderr=out, stdout=out)
      subprocess.call(['pkill', '-P', str(process.pid)], stderr=out, stdout=out)
      # Kill the parent 
      process.terminate()

toolset/setup/linux/TFBReaper.c

@@ -40,12 +40,6 @@ int main(int argc, char *argv[])
  // See: http://man7.org/linux/man-pages/man2/prctl.2.html
  prctl(PR_SET_CHILD_SUBREAPER,1);

  // Sets the process group id to that of the process id of
  // this process. All child processes should inherit this
  // group id unless setpgrp is called directly (which some
  // will do).
  setpgrp();

  // This invokes whatever was passed as arguments to TFBReaper
  // on the system. This program is merely a pass-through to
  // a shell with the subreaper stuff enabled.