共有ライブラリファイル on macOS

macOS Big Sur 11.0.1以降では、システム提供される共有ライブラリファイル(dylib)はファイルシステム上に実体が存在しない。

macOS Big Sur 11.0.1 リリースノートより引用(下線部は強調)。

New in macOS Big Sur 11.0.1, the system ships with a built-in dynamic linker cache of all system-provided libraries. As part of this change, copies of dynamic libraries are no longer present on the filesystem. Code that attempts to check for dynamic library presence by looking for a file at a path or enumerating a directory will fail. Instead, check for library presence by attempting to dlopen() the path, which will correctly check for the library in the cache. (62986286)

macOS Big Sur 11.0.1 Release Notes | Apple Developer Documentation

macOS Ventura 13.4.1での実行結果:

$ otool -L /usr/bin/otool
    /usr/lib/libxcselect.dylib (compatibility version 1.0.0, current version 1.0.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1319.100.3)
$ file /usr/lib/libSystem.B.dylib
/usr/lib/libSystem.B.dylib: cannot open `/usr/lib/libSystem.B.dylib' (No such file or directory)