COPY_PHASE_STRIP support in copy-frameworks is broken

• carthage install method: [ ] .pkg, [x] homebrew, [ ] source
• which carthage: /usr/local/bin/carthage
• carthage version: 0.33.0 & 0.34.0
• xcodebuild -version: Xcode 10.1 Build version 10B61 & Xcode 11.3.1 Build version 11C504
• Are you using --no-build? No
• Are you using --no-use-binaries? No
• Are you using --use-submodules? No
• Are you using --cache-builds? No
• Are you using --new-resolver? No

Cartfile

github "sparkle-project/Sparkle" == 1.19.0

Carthage Output

PhaseScriptExecution carthage\ copy-frameworks /Users/travis/build/griff/metaz/build/MetaZ.build/Release/MetaZ.build/Script-1BA9B57B2089550F00DDC17F.sh (in target 'MetaZ' from project 'MetaZ')
2309 cd /Users/travis/build/griff/metaz
2310 /bin/sh -c /Users/travis/build/griff/metaz/build/MetaZ.build/Release/MetaZ.build/Script-1BA9B57B2089550F00DDC17F.sh
23110.34.0
2312A shell task (/usr/bin/xcrun codesign --force --sign - --preserve-metadata=identifier,entitlements /Users/travis/build/griff/metaz/build/Release/MetaZ.app/Contents/Frameworks/Sparkle.framework) failed with exit code 1:
2313/Users/travis/build/griff/metaz/build/Release/MetaZ.app/Contents/Frameworks/Sparkle.framework: bundle format is ambiguous (could be app or framework)

Actual outcome Whenever COPY_PHASE_STRIP is set to YES carthage copies the Sparkle framework into the app folder but strips the framework incorrectly because the binary in the root of the framework is not a symbolic link as it should be and that breaks code signing.

$ ls -la build/Release/MetaZ.app/Contents/Frameworks/Sparkle.framework
total 984
drwxr-xr-x   5 bro  staff     170 Mar  9 15:56 .
drwxr-xr-x  19 bro  staff     646 Mar  9 15:56 ..
lrwxr-xr-x   1 bro  staff      26 Jul 22  2019 Resources -> Versions/Current/Resources
-rwxr-xr-x   1 bro  staff  499572 Mar  9 15:56 Sparkle
drwxr-xr-x   4 bro  staff     136 Jul 22  2019 Versions

Expected outcome When COPY_PHASE_STRIP is set to NO then carthage copy-framework copies the framework correctly with a symlink in the root. I expected Carthage to do the same when stripping the framework.

$ ls -la build/Debug/MetaZ.app/Contents/Frameworks/Sparkle.framework
total 16
drwxr-xr-x   5 bro  staff  170 Mar  9 15:49 .
drwxr-xr-x  20 bro  staff  680 Mar  9 15:50 ..
lrwxr-xr-x   1 bro  staff   26 Jul 22  2019 Resources -> Versions/Current/Resources
lrwxr-xr-x   1 bro  staff   24 Jul 22  2019 Sparkle -> Versions/Current/Sparkle
drwxr-xr-x   4 bro  staff  136 Jul 22  2019 Versions