I understand what the *.tbd files are doing however what I don't understand is why when I look at the install-name: key there is a path for the actual *.dylib library however I cannot see these, they don't exist with ls. For example below is the head of the MacOSX11.3.sdk/usr/lib/libblas.tbd yaml file: --- !tapi-tbd tbd-version: 4 targets: [ x86_64-macos, x86_64-maccatalyst, x86_64h-macos, x86_64h-maccatalyst, arm64-macos, arm64-maccatalyst, arm64e-macos, arm64e-maccatalyst ] uuids: - target: x86_64-macos value: 86F0C2E1-6A2D-34E8-AA84-D4224BB49B33 - target: x86_64-maccatalyst value: 86F0C2E1-6A2D-34E8-AA84-D4224BB49B33 - target: x86_64h-macos value: 8151F97D-CE36-3B38-AEF0-AAC55E9F537B - target: x86_64h-maccatalyst value: 8151F97D-CE36-3B38-AEF0-AAC55E9F537B - target: arm64-macos value: 00000000-0000-0000-0000-000000000000 - target: arm64-maccatalyst value: 00000000-0000-0000-0000-000000000000 - target: arm64e-macos value: 46295B04-B6A4-36A1-A4F7-C9B606CF75A5 - target: arm64e-maccatalyst value: 46295B04-B6A4-36A1-A4F7-C9B606CF75A5 install-name: '/System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib' exports: - targets: [ arm64e-macos, x86_64-macos, x86_64h-macos, x86_64-maccatalyst, It says the install-name is /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib But I cannot see this file and I am afraid neither can the projects I am trying to compile with cmake/make. $ ls /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib ls: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib: No such file or directory