Fix fatal crash caused by force unwrap

Package.resolved

@@ -27,6 +27,24 @@
           "revision": "5d66f7ba25daf4f94100e7022febf3c75e37a6c7",
           "version": "1.4.2"
         }
+      },
+      {
+        "package": "swift-nio",
+        "repositoryURL": "https://github.com/apple/swift-nio.git",
+        "state": {
+          "branch": null,
+          "revision": "37e7a33de45bac894c0b08b56a2f755ebe4884e6",
+          "version": "2.35.0"
+        }
+      },
+      {
+        "package": "SwiftBacktrace",
+        "repositoryURL": "https://github.com/norio-nomura/SwiftBacktrace",
+        "state": {
+          "branch": null,
+          "revision": "1b4bbe87c19d5e2e04786d8140ab36fec4b7881b",
+          "version": "1.0.1"
+        }
       }
     ]
   },

Package.swift

@@ -9,13 +9,15 @@ let package = Package(
   dependencies: [
     .package(url: "https://github.com/apple/swift-argument-parser", from: "1.0.0"),
     .package(name: "DeltaLogger", url: "https://github.com/stackotter/delta-logger", .branch("main")),
+    .package(url: "https://github.com/norio-nomura/SwiftBacktrace", from: "1.0.1"),
   ],
   targets: [
     .target(
       name: "swift-bundler",
       dependencies: [
         .product(name: "ArgumentParser", package: "swift-argument-parser"),
         "DeltaLogger",
+        "SwiftBacktrace"
       ]),
   ]
 )

Sources/swift-bundler/Subcommands/Build.swift

@@ -89,8 +89,14 @@ extension Bundler {
       } else if line.starts(with: "[") {
         let parts = line.split(separator: "]")
         let progressParts = parts[0].dropFirst().split(separator: "/")
-        let progress = Double(progressParts[0])!
-        let total = Double(progressParts[1])!
+
+        guard
+          let progress = Double(progressParts[0]),
+          let total = Double(progressParts[1])
+        else {
+          return
+        }
+
         let decimalProgress = progress / total
         updateProgress(line, 0.8 * decimalProgress + 0.1, shouldLog: false)
       } else if line.starts(with: "Fetching") || line.starts(with: "Resolving") || line.starts(with: "Cloning") {
@@ -128,4 +134,4 @@ extension Bundler {
 
     updateProgress("Build completed", 1)
   }
-}
+}

Sources/swift-bundler/main.swift

@@ -1,4 +1,23 @@
+import Foundation
+import SwiftBacktrace
+
+NSSetUncaughtExceptionHandler { (exception) in
+  let stack = exception.callStackReturnAddresses
+  print("Stack trace: \(stack)")
+}
+
+func handleSignal(_ code: Int32) {
+  print("caught crash")
+}
+
+signal(SIGABRT, handleSignal);
+signal(SIGILL, handleSignal);
+signal(SIGSEGV, handleSignal);
+signal(SIGFPE, handleSignal);
+signal(SIGBUS, handleSignal);
+signal(SIGPIPE, handleSignal);
+
 Bundler.main()
 
 // TODO: support sandboxing
-// TODO: add proper help messages to subcommands, options and flags
+// TODO: add proper help messages to subcommands, options and flags

install.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 # Build
-swift build -c release
+swift build -c debug
 
 # Create directory with correct permissions
 sudo mkdir -p -m755 /opt/swift-bundler