[AltServer] Improves ALTServerErrorIncompatibleDeveloperDisk error message

Uses NSError’s debug description, if available, to populate error alerts.

AltServer/AppDelegate.swift

@@ -319,7 +319,12 @@ private extension AppDelegate
         
         if let errorFailure = nsError.localizedFailure
         {
-            if let failureReason = nsError.localizedFailureReason
+            if let debugDescription = nsError.localizedDebugDescription
+            {
+                alert.messageText = errorFailure
+                messageComponents.append(debugDescription)
+            }
+            else if let failureReason = nsError.localizedFailureReason
             {
                 if nsError.localizedDescription.starts(with: errorFailure)
                 {
@@ -352,7 +357,15 @@ private extension AppDelegate
         else
         {
             alert.messageText = localizedFailure
-            messageComponents.append(nsError.localizedDescription)
+            
+            if let debugDescription = nsError.localizedDebugDescription
+            {
+                messageComponents.append(debugDescription)
+            }
+            else
+            {
+                messageComponents.append(nsError.localizedDescription)
+            }
         }
         
         if let recoverySuggestion = nsError.localizedRecoverySuggestion

AltServer/Devices/ALTDeviceManager.mm

@@ -1219,6 +1219,7 @@ NSNotificationName const ALTDeviceManagerDeviceDidDisconnectNotification = @"ALT
                 // Connection failed with .unknown error code, so we assume the developer disk is NOT compatible.
                 NSMutableDictionary *userInfo = [@{
                     ALTOperatingSystemVersionErrorKey: NSStringFromOperatingSystemVersion(altDevice.osVersion),
+                    NSFilePathErrorKey: diskURL.path,
                     NSUnderlyingErrorKey: error,
                 } mutableCopy];
                 

Shared/Categories/NSError+ALTServerError.m

@@ -33,6 +33,10 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
         {
             return [error altserver_localizedRecoverySuggestion];
         }
+        else if ([userInfoKey isEqualToString:NSDebugDescriptionErrorKey])
+        {
+            return [error altserver_localizedDebugDescription];
+        }
         
         return nil;
     }];
@@ -172,6 +176,28 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
     }
 }
 
+- (nullable NSString *)altserver_localizedDebugDescription
+{
+    switch ((ALTServerError)self.code)
+    {
+        case ALTServerErrorIncompatibleDeveloperDisk:
+        {
+            NSString *path = self.userInfo[NSFilePathErrorKey];
+            if (path == nil)
+            {
+                return nil;
+            }
+
+            NSString *osVersion = [self altserver_osVersion] ?: NSLocalizedString(@"this device's OS version", @"");
+            NSString *debugDescription = [NSString stringWithFormat:NSLocalizedString(@"The Developer disk located at\n\n%@\n\nis incompatible with %@.", @""), path, osVersion];
+            return debugDescription;
+        }
+            
+        default:
+            return nil;
+    }
+}
+
 - (NSString *)profileErrorLocalizedDescriptionWithBaseDescription:(NSString *)baseDescription
 {
     NSString *localizedDescription = nil;

Shared/Extensions/NSError+AltStore.swift

@@ -16,6 +16,12 @@ extension NSError
         return localizedFailure
     }
     
+    @objc(alt_localizedDebugDescription)
+    var localizedDebugDescription: String? {
+        let debugDescription = (self.userInfo[NSDebugDescriptionErrorKey] as? String) ?? (NSError.userInfoValueProvider(forDomain: self.domain)?(self, NSDebugDescriptionErrorKey) as? String)
+        return debugDescription
+    }
+    
     @objc(alt_errorWithLocalizedFailure:)
     func withLocalizedFailure(_ failure: String) -> NSError
     {