Attach to process

Prerequisites for Ubuntu

On Ubuntu and some other Linux distributions, you might get the ptrace: Operation not permitted error message upon the first attempt to attach to a process. Do one of the following:

1. To disable this restriction temporarily, enter the command:

   echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope

2. To disable this restriction permanently, open the /etc/sysctl.d/10-ptrace.conf file for editing and change the line kernel.yama.ptrace_scope = 1 to kernel.yama.ptrace_scope = 0.

   To apply the changes immediately, enter the above command echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope.

   Alternatively, run sudo service procps restart or restart your system.

You can find more details here.

Attach to a process

1. Press Ctrl+Alt+F5 or select Run | Attach to Process from the main menu.

   The Attach to Process dialog opens the list of all the detected running processes.

   You can view the processes as a list or as a tree and search for a particular process by name:

   

   For each process, you can find the executable name and process ID, the user that launched it, the available debuggers, and the command used for launching.

   Use the drop-down menu to filter the list of processes by the type of the debugger:

   

   You can also filter the list by setting Show only my processes:

   

2. The Local tab shows the list of local processes. Select the process and click Attach with....

   Switch to the SSH tab to view the list of remote processes. Make sure to configure a remote toolchain with SSH credentials beforehand.

   

   On Windows, switch to the WSL tab to open the list of WSL processes. You will be able to attach to them with the WSL GDB debugger (if you have at least one WSL toolchain configured in your project).

3. Proceed with debugging the same way as you usually do it in CLion (set breakpoints, step through, pause and resume the process, evaluate expressions, and so on).

Detach from a process

The procedure of detaching from a remote process is the same as for stopping a debug session. However, note that when you detach, the debug session closes but the process continues to run.

• Click the Stop button on the main toolbar on in the Debug tool window.

• Alternatively, click Stop on the main toolbar or press Ctrl+F2, then select the session to be closed.