Xcode10.0 (10A254a) generate a much larger artifact than Xcode9.4.1(9F2000)

Hello, I am iOS engineer of Bilibili Inc.

We are developing new feature for iOS12 and found an issue for actool.

The actool in Xcode10 toolchain will create a much larger assets.car than Xcode9.4.1

Compile command from Xcode:

actool --output-format human-readable-text --notices --warnings --compress-pngs --enable-on-demand-resources YES --target-device iphone --target-device ipad --minimum-deployment-target 8.0 --platform iphoneos --product-type com.apple.product-type.application --compile output Media.xcassets && ls -al output

https://forums.developer.apple.com/servlet/JiveServlet/downloadImage/2-330768-53552/pastedImage_4.png

In our app this issue will make us 10MB larger than before (Xcode9 vs Xcode10)

https://forums.developer.apple.com/servlet/JiveServlet/downloadImage/2-330768-53553/pastedImage_5.png

https://forums.developer.apple.com/servlet/JiveServlet/downloadImage/2-330768-53554/pastedImage_6.png