# File lib/mkmf.rb, line 551
def checking_for(m, fmt = nil)
  f = caller[0][/in `(.*)'$/, 1] and f << ": " #` for vim
  m = "checking #{/\Acheck/ =~ f ? '' : 'for '}#{m}... "
  message "%s", m
  a = r = nil
  Logging::postpone do
    r = yield
    a = (fmt ? fmt % r : r ? "yes" : "no") << "\n"
    "#{f}#{m}-------------------- #{a}\n"
  end
  message(a)
  Logging::message "--------------------\n\n"
  r
end