I have created an aurora/corona based subtheme. All my gems are up-to-date. For some reason, the susy-background-grid mixin does not work.

Example
I created a file test.scss in the sass folder with the following content:

@import 'aurora/susy-grid';
#page {
  @include container;
  @include susy-grid-background;
}

The output is as expected:
*,
*:after,
*:before {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
img, video {
  max-width: 100%;
  height: auto;
}
#page {
  *zoom: 1;
  max-width: 59em;
  _width: 59em;
  padding-left: 1em;
  padding-right: 1em;
  margin-left: auto;
  margin-right: auto;
  background-image: -webkit-gradient(linear, 0% 50%, 100% 50%, color-stop(0%, rgba(0, 0, 0, 0)), color-stop(0%, rgba(100, 100, 225, 0.25)), color-stop(6.77966%, rgba(100, 100, 225, 0.25)), color-stop(6.77966%, rgba(0, 0, 0, 0)), color-stop(8.47458%, rgba(0, 0, 0, 0)), color-stop(8.47458%, rgba(100, 100, 225, 0.25)), color-stop(15.25424%, rgba(100, 100, 225, 0.25)), color-stop(15.25424%, rgba(0, 0, 0, 0)), color-stop(16.94915%, rgba(0, 0, 0, 0)), color-stop(16.94915%, rgba(100, 100, 225, 0.25)), color-stop(23.72881%, rgba(100, 100, 225, 0.25)), color-stop(23.72881%, rgba(0, 0, 0, 0)), color-stop(25.42373%, rgba(0, 0, 0, 0)), color-stop(25.42373%, rgba(100, 100, 225, 0.25)), color-stop(32.20339%, rgba(100, 100, 225, 0.25)), color-stop(32.20339%, rgba(0, 0, 0, 0)), color-stop(33.89831%, rgba(0, 0, 0, 0)), color-stop(33.89831%, rgba(100, 100, 225, 0.25)), color-stop(40.67797%, rgba(100, 100, 225, 0.25)), color-stop(40.67797%, rgba(0, 0, 0, 0)), color-stop(42.37288%, rgba(0, 0, 0, 0)), color-stop(42.37288%, rgba(100, 100, 225, 0.25)), color-stop(49.15254%, rgba(100, 100, 225, 0.25)), color-stop(49.15254%, rgba(0, 0, 0, 0)), color-stop(50.84746%, rgba(0, 0, 0, 0)), color-stop(50.84746%, rgba(100, 100, 225, 0.25)), color-stop(57.62712%, rgba(100, 100, 225, 0.25)), color-stop(57.62712%, rgba(0, 0, 0, 0)), color-stop(59.32203%, rgba(0, 0, 0, 0)), color-stop(59.32203%, rgba(100, 100, 225, 0.25)), color-stop(66.10169%, rgba(100, 100, 225, 0.25)), color-stop(66.10169%, rgba(0, 0, 0, 0)), color-stop(67.79661%, rgba(0, 0, 0, 0)), color-stop(67.79661%, rgba(100, 100, 225, 0.25)), color-stop(74.57627%, rgba(100, 100, 225, 0.25)), color-stop(74.57627%, rgba(0, 0, 0, 0)), color-stop(76.27119%, rgba(0, 0, 0, 0)), color-stop(76.27119%, rgba(100, 100, 225, 0.25)), color-stop(83.05085%, rgba(100, 100, 225, 0.25)), color-stop(83.05085%, rgba(0, 0, 0, 0)), color-stop(84.74576%, rgba(0, 0, 0, 0)), color-stop(84.74576%, rgba(100, 100, 225, 0.25)), color-stop(91.52542%, rgba(100, 100, 225, 0.25)), color-stop(91.52542%, rgba(0, 0, 0, 0)), color-stop(93.22034%, rgba(0, 0, 0, 0)), color-stop(93.22034%, rgba(100, 100, 225, 0.25)), color-stop(100.0%, rgba(100, 100, 225, 0.25)), color-stop(100.0%, rgba(0, 0, 0, 0)), color-stop(100%, rgba(0, 0, 0, 0)));
  background-image: -webkit-linear-gradient(left, rgba(0, 0, 0, 0) 0%, rgba(100, 100, 225, 0.25) 0%, rgba(100, 100, 225, 0.25) 6.77966%, rgba(0, 0, 0, 0) 6.77966%, rgba(0, 0, 0, 0) 8.47458%, rgba(100, 100, 225, 0.25) 8.47458%, rgba(100, 100, 225, 0.25) 15.25424%, rgba(0, 0, 0, 0) 15.25424%, rgba(0, 0, 0, 0) 16.94915%, rgba(100, 100, 225, 0.25) 16.94915%, rgba(100, 100, 225, 0.25) 23.72881%, rgba(0, 0, 0, 0) 23.72881%, rgba(0, 0, 0, 0) 25.42373%, rgba(100, 100, 225, 0.25) 25.42373%, rgba(100, 100, 225, 0.25) 32.20339%, rgba(0, 0, 0, 0) 32.20339%, rgba(0, 0, 0, 0) 33.89831%, rgba(100, 100, 225, 0.25) 33.89831%, rgba(100, 100, 225, 0.25) 40.67797%, rgba(0, 0, 0, 0) 40.67797%, rgba(0, 0, 0, 0) 42.37288%, rgba(100, 100, 225, 0.25) 42.37288%, rgba(100, 100, 225, 0.25) 49.15254%, rgba(0, 0, 0, 0) 49.15254%, rgba(0, 0, 0, 0) 50.84746%, rgba(100, 100, 225, 0.25) 50.84746%, rgba(100, 100, 225, 0.25) 57.62712%, rgba(0, 0, 0, 0) 57.62712%, rgba(0, 0, 0, 0) 59.32203%, rgba(100, 100, 225, 0.25) 59.32203%, rgba(100, 100, 225, 0.25) 66.10169%, rgba(0, 0, 0, 0) 66.10169%, rgba(0, 0, 0, 0) 67.79661%, rgba(100, 100, 225, 0.25) 67.79661%, rgba(100, 100, 225, 0.25) 74.57627%, rgba(0, 0, 0, 0) 74.57627%, rgba(0, 0, 0, 0) 76.27119%, rgba(100, 100, 225, 0.25) 76.27119%, rgba(100, 100, 225, 0.25) 83.05085%, rgba(0, 0, 0, 0) 83.05085%, rgba(0, 0, 0, 0) 84.74576%, rgba(100, 100, 225, 0.25) 84.74576%, rgba(100, 100, 225, 0.25) 91.52542%, rgba(0, 0, 0, 0) 91.52542%, rgba(0, 0, 0, 0) 93.22034%, rgba(100, 100, 225, 0.25) 93.22034%, rgba(100, 100, 225, 0.25) 100.0%, rgba(0, 0, 0, 0) 100.0%, rgba(0, 0, 0, 0) 100%);
  background-image: -moz-linear-gradient(left, rgba(0, 0, 0, 0) 0%, rgba(100, 100, 225, 0.25) 0%, rgba(100, 100, 225, 0.25) 6.77966%, rgba(0, 0, 0, 0) 6.77966%, rgba(0, 0, 0, 0) 8.47458%, rgba(100, 100, 225, 0.25) 8.47458%, rgba(100, 100, 225, 0.25) 15.25424%, rgba(0, 0, 0, 0) 15.25424%, rgba(0, 0, 0, 0) 16.94915%, rgba(100, 100, 225, 0.25) 16.94915%, rgba(100, 100, 225, 0.25) 23.72881%, rgba(0, 0, 0, 0) 23.72881%, rgba(0, 0, 0, 0) 25.42373%, rgba(100, 100, 225, 0.25) 25.42373%, rgba(100, 100, 225, 0.25) 32.20339%, rgba(0, 0, 0, 0) 32.20339%, rgba(0, 0, 0, 0) 33.89831%, rgba(100, 100, 225, 0.25) 33.89831%, rgba(100, 100, 225, 0.25) 40.67797%, rgba(0, 0, 0, 0) 40.67797%, rgba(0, 0, 0, 0) 42.37288%, rgba(100, 100, 225, 0.25) 42.37288%, rgba(100, 100, 225, 0.25) 49.15254%, rgba(0, 0, 0, 0) 49.15254%, rgba(0, 0, 0, 0) 50.84746%, rgba(100, 100, 225, 0.25) 50.84746%, rgba(100, 100, 225, 0.25) 57.62712%, rgba(0, 0, 0, 0) 57.62712%, rgba(0, 0, 0, 0) 59.32203%, rgba(100, 100, 225, 0.25) 59.32203%, rgba(100, 100, 225, 0.25) 66.10169%, rgba(0, 0, 0, 0) 66.10169%, rgba(0, 0, 0, 0) 67.79661%, rgba(100, 100, 225, 0.25) 67.79661%, rgba(100, 100, 225, 0.25) 74.57627%, rgba(0, 0, 0, 0) 74.57627%, rgba(0, 0, 0, 0) 76.27119%, rgba(100, 100, 225, 0.25) 76.27119%, rgba(100, 100, 225, 0.25) 83.05085%, rgba(0, 0, 0, 0) 83.05085%, rgba(0, 0, 0, 0) 84.74576%, rgba(100, 100, 225, 0.25) 84.74576%, rgba(100, 100, 225, 0.25) 91.52542%, rgba(0, 0, 0, 0) 91.52542%, rgba(0, 0, 0, 0) 93.22034%, rgba(100, 100, 225, 0.25) 93.22034%, rgba(100, 100, 225, 0.25) 100.0%, rgba(0, 0, 0, 0) 100.0%, rgba(0, 0, 0, 0) 100%);
  background-image: -o-linear-gradient(left, rgba(0, 0, 0, 0) 0%, rgba(100, 100, 225, 0.25) 0%, rgba(100, 100, 225, 0.25) 6.77966%, rgba(0, 0, 0, 0) 6.77966%, rgba(0, 0, 0, 0) 8.47458%, rgba(100, 100, 225, 0.25) 8.47458%, rgba(100, 100, 225, 0.25) 15.25424%, rgba(0, 0, 0, 0) 15.25424%, rgba(0, 0, 0, 0) 16.94915%, rgba(100, 100, 225, 0.25) 16.94915%, rgba(100, 100, 225, 0.25) 23.72881%, rgba(0, 0, 0, 0) 23.72881%, rgba(0, 0, 0, 0) 25.42373%, rgba(100, 100, 225, 0.25) 25.42373%, rgba(100, 100, 225, 0.25) 32.20339%, rgba(0, 0, 0, 0) 32.20339%, rgba(0, 0, 0, 0) 33.89831%, rgba(100, 100, 225, 0.25) 33.89831%, rgba(100, 100, 225, 0.25) 40.67797%, rgba(0, 0, 0, 0) 40.67797%, rgba(0, 0, 0, 0) 42.37288%, rgba(100, 100, 225, 0.25) 42.37288%, rgba(100, 100, 225, 0.25) 49.15254%, rgba(0, 0, 0, 0) 49.15254%, rgba(0, 0, 0, 0) 50.84746%, rgba(100, 100, 225, 0.25) 50.84746%, rgba(100, 100, 225, 0.25) 57.62712%, rgba(0, 0, 0, 0) 57.62712%, rgba(0, 0, 0, 0) 59.32203%, rgba(100, 100, 225, 0.25) 59.32203%, rgba(100, 100, 225, 0.25) 66.10169%, rgba(0, 0, 0, 0) 66.10169%, rgba(0, 0, 0, 0) 67.79661%, rgba(100, 100, 225, 0.25) 67.79661%, rgba(100, 100, 225, 0.25) 74.57627%, rgba(0, 0, 0, 0) 74.57627%, rgba(0, 0, 0, 0) 76.27119%, rgba(100, 100, 225, 0.25) 76.27119%, rgba(100, 100, 225, 0.25) 83.05085%, rgba(0, 0, 0, 0) 83.05085%, rgba(0, 0, 0, 0) 84.74576%, rgba(100, 100, 225, 0.25) 84.74576%, rgba(100, 100, 225, 0.25) 91.52542%, rgba(0, 0, 0, 0) 91.52542%, rgba(0, 0, 0, 0) 93.22034%, rgba(100, 100, 225, 0.25) 93.22034%, rgba(100, 100, 225, 0.25) 100.0%, rgba(0, 0, 0, 0) 100.0%, rgba(0, 0, 0, 0) 100%);
  background-image: linear-gradient(left, rgba(0, 0, 0, 0) 0%, rgba(100, 100, 225, 0.25) 0%, rgba(100, 100, 225, 0.25) 6.77966%, rgba(0, 0, 0, 0) 6.77966%, rgba(0, 0, 0, 0) 8.47458%, rgba(100, 100, 225, 0.25) 8.47458%, rgba(100, 100, 225, 0.25) 15.25424%, rgba(0, 0, 0, 0) 15.25424%, rgba(0, 0, 0, 0) 16.94915%, rgba(100, 100, 225, 0.25) 16.94915%, rgba(100, 100, 225, 0.25) 23.72881%, rgba(0, 0, 0, 0) 23.72881%, rgba(0, 0, 0, 0) 25.42373%, rgba(100, 100, 225, 0.25) 25.42373%, rgba(100, 100, 225, 0.25) 32.20339%, rgba(0, 0, 0, 0) 32.20339%, rgba(0, 0, 0, 0) 33.89831%, rgba(100, 100, 225, 0.25) 33.89831%, rgba(100, 100, 225, 0.25) 40.67797%, rgba(0, 0, 0, 0) 40.67797%, rgba(0, 0, 0, 0) 42.37288%, rgba(100, 100, 225, 0.25) 42.37288%, rgba(100, 100, 225, 0.25) 49.15254%, rgba(0, 0, 0, 0) 49.15254%, rgba(0, 0, 0, 0) 50.84746%, rgba(100, 100, 225, 0.25) 50.84746%, rgba(100, 100, 225, 0.25) 57.62712%, rgba(0, 0, 0, 0) 57.62712%, rgba(0, 0, 0, 0) 59.32203%, rgba(100, 100, 225, 0.25) 59.32203%, rgba(100, 100, 225, 0.25) 66.10169%, rgba(0, 0, 0, 0) 66.10169%, rgba(0, 0, 0, 0) 67.79661%, rgba(100, 100, 225, 0.25) 67.79661%, rgba(100, 100, 225, 0.25) 74.57627%, rgba(0, 0, 0, 0) 74.57627%, rgba(0, 0, 0, 0) 76.27119%, rgba(100, 100, 225, 0.25) 76.27119%, rgba(100, 100, 225, 0.25) 83.05085%, rgba(0, 0, 0, 0) 83.05085%, rgba(0, 0, 0, 0) 84.74576%, rgba(100, 100, 225, 0.25) 84.74576%, rgba(100, 100, 225, 0.25) 91.52542%, rgba(0, 0, 0, 0) 91.52542%, rgba(0, 0, 0, 0) 93.22034%, rgba(100, 100, 225, 0.25) 93.22034%, rgba(100, 100, 225, 0.25) 100.0%, rgba(0, 0, 0, 0) 100.0%, rgba(0, 0, 0, 0) 100%);
  background-position: left top;
  -webkit-background-origin: content;
  -moz-background-origin: content;
  -ms-background-origin: content-box;
  -o-background-origin: content-box;
  background-origin: content-box;
  -webkit-background-clip: content-box;
  -moz-background-clip: content-box;
  background-clip: content-box;
}
#page:after {
  content: "";
  display: table;
  clear: both;
}

These long background-image styles are the grid background.

Now, when I add the following lines to _global.scss:
/* grid */
#page {
  @include container;
  @include susy-grid-background;
}
/* end grid */

it only results in the following CSS:
/* grid */
#page {
  max-width: 59em;
  padding-left: 1em;
  padding-right: 1em;
  margin-left: auto;
  margin-right: auto;
  -webkit-background-origin: content;
  -moz-background-origin: content;
  -ms-background-origin: content-box;
  -o-background-origin: content-box;
  background-origin: content-box;
  -webkit-background-clip: content-box;
  -moz-background-clip: content-box;
  background-clip: content-box;
}
#page:after {
  content: "";
  display: table;
  clear: both;
}
/* end grid */

As you can see, the background grid is gone.

Comments

Have you tried adding:
@import 'aurora/susy-grid';
to the _global.scss?

I'm not sure if I tried that, but I sure did now :-) When I add this to _global.scss:

/* grid */
@import 'aurora/susy-grid';
#page {
  @include container;
  @include susy-grid-background;
}
/* end grid */

the result is:
/* grid */
*,
*:after,
*:before {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
img, video {
  max-width: 100%;
  height: auto;
}
#page {
  max-width: 45em;
  padding-left: 0.5em;
  padding-right: 0.5em;
  margin-left: auto;
  margin-right: auto;
  -webkit-background-origin: content;
  -moz-background-origin: content;
  -ms-background-origin: content-box;
  -o-background-origin: content-box;
  background-origin: content-box;
  -webkit-background-clip: content-box;
  -moz-background-clip: content-box;
  background-clip: content-box;
}
#page:after {
  content: "";
  display: table;
  clear: both;
}
/* end grid */

So unfortunately, that doesn't work.

I remember now!! In your _variables.scss set $show-grid-backgrounds : to true;

Status:Active» Closed (works as designed)

Yup--- that is part of susy.

$show-grid-backgrounds: true;

must be in your code for this to work properly.

Thank you James! $show-grid-backgrounds: true; did the trick. For some reason I didn't notice it in the variables partial.

Looking at my test.scss above, it seems that this is an undocumented (ie. not listed on http://susy.oddbird.net/guides/reference/ ) setting which defaults to true, but aurora sets it to false in _variables.scss.

Anyway, I'm glad it works now.

Issue summary:View changes

fix incorrectly pasted code