hardly interpretable swift error while code execution

[Lausbert]

While trying to "attempt" the "Some Egyptian fractions" kata I got an error I don't know how to solve, even after research. "Run Sample Tests" is working fine. Name on codewars is Lausbert.

Solution:

func decompose(_ nrStr: String, _ drStr: String) -> String {

    guard var nr = Int(nrStr), var dr = Int(drStr) else {return "input error"}
    let nrDrGcd = gcd(nr, dr)
    nr = nr/nrDrGcd; dr = dr/nrDrGcd

    if nrStr == "1" {return String(nr) + "/" + String(dr)}

    if nr/dr >= 1 {return String(nr/dr)}
    let subtractDr = dr/nr + 1

    subtract(&nr, &dr, subtractDr)
    return "1/" + String(subtractDr) + "," + decompose(String(nr), String(dr))
}

func subtract(_ nr: inout Int, _ dr: inout Int, _ subtractDr: Int) {
    let drLcm = lcm(dr, subtractDr)
    let factorOne = drLcm/dr, factorTwo = drLcm/subtractDr
    nr = factorOne*nr-factorTwo
    dr = drLcm
}

func gcd(_ a : Int, _ b : Int) -> Int {
    var b = b, a = a
    while b != 0 {
        (a, b) = (b, a % b)
    }
    return abs(a)
}

func lcm( _ a : Int, _ b : Int) -> Int {
    return (a / gcd(a, b)) * b
}

Error:

0  swift           0x00000000034bf568 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1  swift           0x00000000034c0146
2  libpthread.so.0 0x00007f2a5b910330
3  libpthread.so.0 0x00007f2a5bc857c5
4  libpthread.so.0 0x00007f2a5bc85ea1
5  libpthread.so.0 0x00007f2a5bc872e8
6  libpthread.so.0 0x00007f2a5bc85efb
7  libpthread.so.0 0x00007f2a5bc87395
8  libXCTest.so    0x00007f2a58083641
9  libXCTest.so    0x00007f2a580a2460
10 libXCTest.so    0x00007f2a5809f5c5
11 libXCTest.so    0x00007f2a580a1806
12 libXCTest.so    0x00007f2a580899e0
13 libXCTest.so    0x00007f2a580835c5     _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 101
14 libXCTest.so    0x00007f2a5bc85deb _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 62924939
15 libXCTest.so    0x00007f2a5bc86559 _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 62926841
16 libXCTest.so    0x00007f2a5bc87880 _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 62931744
17 libXCTest.so    0x00007f2a5bc85b5e _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 62924286
18 libXCTest.so    0x00007f2a5bc87815 _TF6XCTest14XCTAssertEqualuRxs9EquatablerFTKzT_xKzT_xKT_SS4fileVs12StaticString4lineSu_T_ + 62931637
19 libXCTest.so    0x00007f2a580b66ab
20 libXCTest.so    0x00007f2a5808d1a2
21 libXCTest.so    0x00007f2a580b6660
22 libXCTest.so    0x00007f2a580b63e0
23 libXCTest.so    0x00007f2a5808c280 _TFC6XCTest10XCTestCase10invokeTestfT_T_ + 112
24 libXCTest.so    0x00007f2a580a4219 _TTSf4g_n___TFC6XCTest10XCTestCase7performfCS_9XCTestRunT_ + 313
25 libXCTest.so    0x00007f2a5808c14e _TFC6XCTest10XCTestCase7performfCS_9XCTestRunT_ + 14
26 libXCTest.so    0x00007f2a5808bf45 _TFC6XCTest6XCTest3runfT_T_ + 629
27 libXCTest.so    0x00007f2a580a4ee5 _TTSf4g_n___TFC6XCTest11XCTestSuite7performfCS_9XCTestRunT_ + 789
28 libXCTest.so    0x00007f2a580a53b3 _TTSf4g_n___TFC6XCTest11XCTestSuite7performfCS_9XCTestRunT_ + 2019
29 libXCTest.so    0x00007f2a580a53b3 _TTSf4g_n___TFC6XCTest11XCTestSuite7performfCS_9XCTestRunT_ + 2019
30 libXCTest.so    0x00007f2a580916db _TF6XCTest7XCTMainFGSaT13testCaseClassMCS_10XCTestCase8allTestsGSaTSSFzS0_T_____Os5Never + 4283
31 libXCTest.so    0x00007f2a5bc850e9 _TF6XCTest7XCTMainFGSaT13testCaseClassMCS_10XCTestCase8allTestsGSaTSSFzS0_T_____Os5Never + 62868169
32 swift           0x0000000000c795f2 llvm::MCJIT::runFunction(llvm::Function*, llvm::ArrayRef<llvm::GenericValue>) + 1042
33 swift           0x0000000000c7d0ff llvm::ExecutionEngine::runFunctionAsMain(llvm::Function*, std::vector<std::string, std::allocator<std::string> > const&, char const* const*) + 1215
34 swift           0x000000000083ca6f swift::RunImmediately(swift::CompilerInstance&, std::vector<std::string, std::allocator<std::string> > const&, swift::IRGenOptions&, swift::SILOptions const&) + 2303
35 swift           0x00000000008364f8
36 swift           0x0000000000831377 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2551
37 swift           0x00000000007f8788 main + 3016
38 libc.so.6       0x00007f2a5a0b9f45 __libc_start_main + 245
39 swift           0x00000000007f5e56
Stack dump:
0.  Program arguments: /swift-vol/swift-gen/usr/bin/swift -frontend -interpret /tmp/swift117614-14-7ri4d6.pqlxnfusor/solution.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name solution

[jhoffner]

@kazk this might be due to the new swift runner.

[jhoffner]

Note that the new runner is up on www but not for red users yet.

Update: actually maybe the new Swift runner didn't get deployed, I'm seeing multiple Passed statements under each spec when I test. That shouldn't be the case (should only ever be one correct?).

[kazk]

@jhoffner I don't think it's the new swift-runner because of 0. Program arguments: /swift-vol/swift-gen/usr/bin/swift. The new image doesn't create volumes.

---

Note that the new runner is up on www

How are the compatibility issues handled? I'm also concerned about how I avoided the concatenation. I can test some on preview if you can deploy it there.

[kazk]

@Lausbert

"Run Sample Tests" is working fine.

Actual tests might contain some edge cases. How are you validating the input? Is it possible to do division by zero somewhere?

[Lausbert]

You were actually right. Thank you and sorry for wasting your time! :)

[kazk]

@Lausbert no problem. I'll look into if we can improve the error output somehow.