I had the same problem in my project using compass 0.12.7, and an unexpected problem can only be solved by updating the compass. A warning about the problem is triggered when using linear-gradient mixing with a position value of to right , as in the following example:
div { @include background(linear-gradient(to right, red, blue)); }
This will compile for something like this (throwing an error in your question):
div { background: -webkit-gradient(linear, to right, to left, color-stop(0%, #ff0000), color-stop(100%, #0000ff)); background: -webkit-linear-gradient(to right, #ff0000, #0000ff); background: -moz-linear-gradient(to right, #ff0000, #0000ff); background: -o-linear-gradient(to right, #ff0000, #0000ff); background: linear-gradient(to right, #ff0000, #0000ff); }
Otherwise, this is invalid CSS code. The correct conclusion should be as follows:
div { background: -webkit-gradient(linear, 0% 50%, 100% 50%, color-stop(0%, #ff0000), color-stop(100%, #0000ff)); background: -moz-linear-gradient(left, #ff0000, #0000ff); background: -webkit-linear-gradient(left, #ff0000, #0000ff); background: linear-gradient(to right, #ff0000, #0000ff); }
The only way to fix this is to update the compass, as I said.