             var output = try popen(execpath)
             XCTAssertEqual(output, "Hello\n")
 
-            // we need to sleep at least one second otherwise
-            // llbuild does not realize the file has changed
-            sleep(1)
-
             try fopen(prefix, "root/Packages/dep1-1.2.3/Foo.swift", mode: .write) { fp in
                 try fputs("public let foo = \"Goodbye\"", fp)
             }

            XCTAssertBuilds(prefix, "app")
            var output = try popen(execpath)
            XCTAssertEqual(output, "♣︎K\n♣︎Q\n♣︎J\n♣︎10\n♣︎9\n♣︎8\n♣︎7\n♣︎6\n♣︎5\n♣︎4\n")

            // we need to sleep at least one second otherwise
            // llbuild does not realize the file has changed
            sleep(1)

            try fopen(prefix, "app/Packages/FisherYates-1.2.3/src/Fisher-Yates_Shuffle.swift", mode: .write) { fp in
                try fputs("public extension Collection{ func shuffle() -> [Iterator.Element] {return []} }\n\npublic extension MutableCollection where Index == Int { mutating func shuffleInPlace() { for (i, _) in enumerated() { self[i] = self[0] } }}\n\npublic let shuffle = true", fp)

            var output = try popen(execpath)
            XCTAssertEqual(output, "Hello\n")

            try fopen(prefix, "Bar/Bar.swift", mode: .write) { fp in
                try fputs("public let bar = \"Goodbye\"\n", fp)
            }
