Arbitrary limit on browser versions?

[thany]

Please consider this code:

$supported-browsers: ("chrome", "firefox", "ie", "safari", "opera");
$browser-minimum-versions: (
  "chrome": "41",
  "firefox": "36",
  "ie": "11",
  "safari": "8",
  "opera": "27"
);

So my application supports only the very latest browsers (hooray!), but it rejects the one for Opera:

error includes/scss/default.scss (Line 331 of C:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/compass-core-1.0.3/stylesheets/compass/_support.scss: 27 is not a version for opera)

I know the current Opera is not really Opera at all, but "opera": "24" does work, so it appears to accept Chropera versions as well.

Why impose a limit on (some) browser versions? This is not the case for Chrome, which I can define with "chrome": "43" and it'll work happily.

For completeness:

• Compass 1.0.3
• Sass 3.4.13
• Gem system 2.4.6
• Ruby 2.1.3p242 x64
• Windows 7 x64