Creating Assets.car file through command line for app resigning

You just need to use the name of your appiconset.

So in this example add:

 --app-icon AppIcons --output-partial-info-plist build/partial.plist

Have getting same issues, but after an hour R&D got success with the below code:

 /Applications/Xcode.app/Contents/Developer/usr/bin/actool Assets.xcassets --compile build --platform iphoneos  --minimum-deployment-target 9.0 --app-icon AppIcon --output-partial-info-plist  myfolder/info.plist

or

/usr/bin/xcrun actool Assets.xcassets --compile build --platform iphoneos --minimum-deployment-target 8.0 --app-icon AppIcon --output-partial-info-plist build/partial.plist

Where you can change platform value and output path {such as myfolder/build is folder name}