I'm following the instructions under Get Started with the Apex Debugger. I'm up to the point where I create a Permission Set for the debugger user to enable the "Debug Apex" permission under System Permissions. Except I can't see that permission.
Do I need to do something else to access it?
Without it the Force.com IDE fails with the following error. (Which I assume is directly related to the permission I can't set)
Your user doesn't have the permission to debug Apex.
I've tried to configure this permission from both a LMA login and direct login as the System Administrator in the sandbox.
The Start Partner Debugging Session button does appear in the Apex debugger setup page. It generates a
forceide: link with a valid session ID.
There isn't much to go on in the Force.com IDE Log Viewer. There is a message:
(DebuggerConnectionException) nnot connect to the remote server (Open log file for full message and/or stacktrace).
This entry doesn't appear in the force-ide.log file.
Note that this corresponds to the Debug Apex Code in Subscriber Orgs Spring '17 feature.