Can't launch - mono fiddle.exe

[Bala]

Hello, I followed the instructions, but got the below exception - 

$ mono fiddler.exe
WARNING: The Carbon driver has not been ported to 64bits, and very few parts of Windows.Forms will work properly, or at all
Stacktrace:
  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) System.Windows.Forms.XplatUICarbon.CGDisplayBounds (intptr) [0x00002] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.XplatUICarbon.get_WorkingArea () [0x00005] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.XplatUICarbon.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.XplatUI.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Screen..cctor () [0x00034] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at (wrapper runtime-invoke) object.runtime_invoke_void (object,intptr,intptr,intptr) [0x0001e] in <98fac219bd4e453693d76fda7bd96ab0>:0
  at <unknown> <0xffffffff>
  at System.Windows.Forms.Form.get_CreateParams () [0x00157] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Control.CreateHandle () [0x0002a] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Form.CreateHandle () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Control.CreateControl () [0x00039] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Control.SetVisibleCore (bool) [0x00057] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Form.SetVisibleCore (bool) [0x00065] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Control.set_Visible (bool) [0x00009] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at System.Windows.Forms.Control.Show () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.Show () [0x00031] in <556a6ba2c0a546f1ad2318c309ce0945>:0
  at Fiddler.frmViewer.‹• (string[]) [0x00081] in <09623c708fdb40a483cea147bbea7a7f>:0
  at Fiddler.frmViewer.‡• (string[]) [0x00016] in <09623c708fdb40a483cea147bbea7a7f>:0
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) [0x0004e] in <09623c708fdb40a483cea147bbea7a7f>:0
exception inside UnhandledException handler: The type initializer for 'System.Windows.Forms.Screen' threw an exception.


[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Windows.Forms.Screen' threw an exception. ---> System.NullReferenceException: Object reference not set to an instance of an object
  at (wrapper managed-to-native) System.Windows.Forms.XplatUICarbon.CGDisplayBounds(intptr)
  at System.Windows.Forms.XplatUICarbon.get_WorkingArea () [0x00005] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at System.Windows.Forms.XplatUICarbon.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at System.Windows.Forms.XplatUI.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at System.Windows.Forms.Screen..cctor () [0x00034] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
   --- End of inner exception stack trace ---
  at System.Windows.Forms.MessageBox+MessageBoxForm.InitFormsSize () [0x00002] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at System.Windows.Forms.MessageBox+MessageBoxForm.RunDialog () [0x0000f] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.MessageBox+MessageBoxForm.RunDialog()
  at System.Windows.Forms.MessageBox.Show (System.Windows.Forms.IWin32Window owner, System.String text, System.String caption, System.Windows.Forms.MessageBoxButtons buttons, System.Windows.Forms.MessageBoxIcon icon) [0x0000b] in <556a6ba2c0a546f1ad2318c309ce0945>:0 
  at Fiddler.FiddlerApplication.DoNotifyUser (System.Windows.Forms.IWin32Window ownerWnd, System.String sMessage, System.String sTitle, System.Windows.Forms.MessageBoxIcon oIcon) [0x0002c] in <09623c708fdb40a483cea147bbea7a7f>:0 
  at Fiddler.FiddlerApplication.DoNotifyUser (System.String sMessage, System.String sTitle, System.Windows.Forms.MessageBoxIcon oIcon) [0x00000] in <09623c708fdb40a483cea147bbea7a7f>:0 
  at Fiddler.FiddlerApplication.ReportException (System.Exception eX, System.String sTitle, System.String sCallerMessage) [0x001a4] in <09623c708fdb40a483cea147bbea7a7f>:0 
  at Fiddler.FiddlerApplication.ReportException (System.Exception ‚) [0x00006] in <09623c708fdb40a483cea147bbea7a7f>:0 
  at Fiddler.frmViewer.• (System.Object, System.UnhandledExceptionEventArgs •) [0x00006] in <09623c708fdb40a483cea147bbea7a7f>:0 

[Bala]

I downloaded mono 5.16.0

[Simeon]

Hi Bala,

Could you please, try the mono --arch=32 Fiddler.exe command.

Regards,
Simeon
Progress Telerik

[Bala]

Hello, I tried 'mono --arch=32 Fiddler.exe and the UI comes up but when I start a capture, it prompts for system password as osascript needs to make a change, but nothing happens further. No capture whatsoever!. Also, it seems to have hosed my corporate VPN connections and I am not able to connect and troubleshooting that part separately. I can't recall when macOS moved from 32 bit to 64 bit but that should be atleast a decade back, what is this mono library and is there no native support for fiddler planned?. 

[Alexander]

Hello,

The prompt for the password is needed in order to change the system proxy settings to use Fiddler as HTTP/S proxy. This enables the capturing. Would it be possible to share screenshots of your active network connection's proxy settings? You can find those by going to System Preferences -> Network -> Advanced -> Proxies -> HTTP and HTTPS.

What VPN software are you using?

Mono is a .NET Framework implementation enabling development of cross-platform applications based on C#/.NET technologies. This was our first attempt to make Fiddler work on Mac and Linux. As you can see it is not very successful, due to various limitations and problems. I think you will like our second attempt more.

Regards,
Alexander
Progress Telerik

[Bala]

Hello Alex, 

I will give the "second attempt" a shot. Meanwhile, I am attaching a screenshot of my mac proxy settings. I had to uncheck http/https proxy settings to get my VPN connection back. We use cisco anyconnect vpn, but I am not sure why it is having problem with fiddler. 

-Bala

[Simeon]

Hi Bala,

Thanks for the reply! Are you able to access the Internet without the proxy in your office or there is a firewall? Your proxy settigns are set to Auto Proxy Discovery. This is still not supported by Fiddler on Mac and Linux. We are using the WinHTTP native API on Windows for this and we are researching for alternatives on Mac and Linux.