I modified the contentsOfDirectory(at:…) arguments as the code comment - https://github.com/apple/swift-corelibs-foundation/blob/main/Sources/Foundation/FileManager.swift#L54 suggests to "only receive the URLs and no other attributes":
swift
let u = URL(fileURLWithPath: "/Users/user")
_ = try! FileManager.default.contentsOfDirectory(atPath: u.path)
mkdir("/Users/user/Test1", 0o755)
_ = try! FileManager.default.contentsOfDirectory(atPath: u.path)
mkdir("/Users/user/Test2", 0o755)
_ = try! FileManager.default.contentsOfDirectory(at: u, includingPropertiesForKeys: [], options: FileManager.DirectoryEnumerationOptions(rawValue: 0))
mkdir("/Users/user/Test3", 0o755)
The output of fs_usage when contentsOfDirectory(at:…) throws a fatal error:
mkdir [ 1] /Users/user/Test1
stat64 /Users/user
getattrlist /Users/user
getattrlist /Users/user
getattrlist /Users/user
open F=4 (R__________X) /Users/user
fstat64 F=4
getattrlistbulk
getattrlist [ 5] /Users/user/mount
getattrlistbulk
getattrlistbulk
close F=4
mkdir [ 1] /Users/user/Test2
getattrlist /Users/user
getattrlist /Users/user
open F=4 (R__________X) /Users/user
fstat64 F=4
getattrlistbulk
getattrlist [ 5] /Users/user/mount
getattrlistbulk
close F=4