gdb fails with “Unable to find Mach task port for process-id” error

Question

My app runs fine but gdb fails to debug it with the following error

(gdb) run
Starting program: /path/to/app 
Unable to find Mach task port for process-id 83         


        

Answer 1

Here is a really useful guide which solved my problem(OSX 10.13.6).

1. Open Keychain Access
2. In the menu, open Keychain Access > Certificate Assistant > Create a certificate
3. Give it a name (e.g. gdbc)
   • Identity type: Self Signed Root
   • Certificate type: Code Signing
   • Check: let me override defaults
4. Continue until it prompts you for: "specify a location for..."
5. Set Keychain location to System
6. Create a certificate and close assistant.
7. Find the certificate in System keychains, right click it > get info (or just double click it)
8. Expand Trust, set Code signing to always trust
9. Restart taskgated in terminal: killall taskgated
10. Run codesign -fs gdbc /usr/local/bin/gdb in terminal: this asks for the root password