SVG use not working in Safari
Safari doesn't support href yet, you need to use xlink:href instead.
href is a new feature of the upcoming SVG 2 specification. xlink:href is the SVG 1.1 version.
Chrome, Firefox and Edge support both xlink:href and href.
Here is an update from the future 2019.
Just add xlink:
<svg role="img">
<use xlink:href="/path/to/svg#id"></use>
</svg>
Works with IOS 12