My version of @hugogiraudel‘s http://codepen.io/HugoGiraudel/pen/unyBH with a shell output.

output.txt

$ sass -t expanded test01.scss
test01.scss:10 DEBUG: list of 3 values:
test01.scss:14 DEBUG:   - (string)  a
test01.scss:14 DEBUG:   - (color)  #bada55
test01.scss:14 DEBUG:   - (number)  42
test01.scss:10 DEBUG: list of 2 values:
test01.scss:14 DEBUG:   - (bool)  false
test01.scss:14 DEBUG:   - (string)  yummy
test01.scss:14 DEBUG: (number)  14px
test01.scss:14 DEBUG: (string)  gloubiboulga

ppm_debug.scss

// @private
@function ppm_debug($prefix, $vars...) {
  $result: '';
  @each $item in $vars {
    $type: type-of($item);
    @if 'list' == $type {
      @debug 'list of #{length($item)} values:';
      $result: ppm_debug('  - ', $item...);
    }
    @else {
      @debug '#{$prefix}(#{$type})  #{$item}';
    }
  }

  @return "";
}

// Display clean debug
@mixin ppm_debug($vars...) {
  $result: ppm_debug('', $vars...);
}

.page {
  @include ppm_debug(a #BADA55 42, false yummy, 14px, "gloubiboulga");
}