rsync on macOS does not support the --ignore-missing-args option

[euanh]

#170 added the --ignore-missing-args flags to the rsync command. Unfortunately the version of rsync provided by current versions of macOS (15.3) does not support this flag:

[23/23] Applying swift-sdk-generator
Build of product 'swift-sdk-generator' complete! (5.63s)
2025-02-13T14:01:38+0000 info org.swift.swift-sdk-generator : packageCount=11 [SwiftSDKGenerator] Downloading Ubuntu packages...
2025-02-13T14:01:39+0000 info org.swift.swift-sdk-generator : [SwiftSDKGenerator] Unpacking Swift distribution for the target triple...
2025-02-13T14:01:42+0000 info org.swift.swift-sdk-generator : [SwiftSDKGenerator] Copying Swift core libraries for the target triple into Swift SDK bundle...
rsync: --ignore-missing-args: unknown option
rsync error: syntax or usage error (code 1) at /AppleInternal/Library/BuildRoots/5bb93434-bef0-11ef-bef2-d285688f7a47/Library/Caches/com.apple.xbs/Sources/rsync/rsync/main.c(1337) [client=2.6.9]

[euanh]

@xtremekforever Could you please see if there's an alternative way of handling missing directories in rsync which works for armv7 SDKs without using this flag?

[xtremekforever]

Oops! I'll have a look today. I'm sure it can be a simple fix.