Hi Quinn, yes, I’m specifically referring to running codesign directly from Terminal. It’s the first case you described: I ran codesign directly from Terminal against a standalone test binary using the same Apple Development identity. That completed successfully, and I later verified the artifact was signed with the expected development certificate. I then ran xcodebuild build-for-testing. The first CodeSign operation performed by that xcodebuild invocation was for libXCTestSwiftSupport.dylib, and that is where the Keychain authorization dialog became unresponsive and the signing operation returned errSecInternalComponent. So it is not a case where one CodeSign step inside the same xcodebuild succeeded and a subsequent one failed. I’ve since reproduced the same authorization-dialog behavior with a brand-new minimal iOS + XCTest project using Product → Build For → Testing, which is the focused sample project I submitted with the DTS case. Happy to provide the exact standalone codesign command and the failing xcodebuild CodeSign block if useful. Thanks, Edmund