Builder is not pre-installed, moreover the original Gnome icon is too different from the one you want to use as reference. I would give a -1 fort this
So on one issue you say extending our icon set to more gnome apps like gimp or inkscape would suddenly make Ubuntu become a bad distribution but then you open an icon request for gnome builder? What weird logic is that?
Funnily enough, I thought Builder was one of the icons that worked really well in @clobrano's script screenshots:


@Feichtmeier,
On the one hand, this is a GNOME core application. On the other hand, application named given name, it can be considered third-party app.
Yes the same can be applied to all gnome applications that are not pre installed
So what logic is that?
If you just agreed that it is no problem to make Yaru icons for popular gnome apps like gimp, inkscape or whatever it would make sense.
IF it should have a new icon, I'm +1 for the script one @ubuntujaggers suggested.
Changing it to something completely different like Xcode, would be very confusing for people coming from other distros (and icon themes) IMO
I think we could try real Suru icons for most gnome apps (including builder) which respect the main idea of the app icon. Like @ubuntujaggers did with the shotwell icon
The script could then fill the gaps of none gnome apps (when I say gnome apps I only mean those currently being actively developed/maintained gtk3 apps)
I'm closing this issue, because Builder is a third-party app.
If you would come up with an idea that represents the new icon from
http://jimmac.musichall.cz/stuff/icon-revolution/
In a Suru style, like @ubuntujaggers did for shotwell, I think that would be the way I personally prefer to the OSX inspiration
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IF it should have a new icon, I'm +1 for the script one @ubuntujaggers suggested.
Changing it to something completely different like Xcode, would be very confusing for people coming from other distros (and icon themes) IMO