"The kit does not have a debugger set." ?

[SPlatten]

Today I continued work on my project, no changes to the project except to Clean and Build All Projects. Everything builds with no issues, when I try to run it I'm now getting:

06:52:06: The kit does not have a debugger set.

Why? I haven't changed anything in the project settings, just the source. I am using:

Qt Creator 8.0.1
Based on Qt 6.3.1 (Clang 13.0 (Apple), x86_64)
Built on Aug 11 2022 01:27:10
From revision 9c963ce8ae

[SPlatten]

@SPlatten , no changes, just come back to it, Clean and Build All Projects now its all ok again...very odd.

[jsulm]

@SPlatten Did you change the Kit you're using? The debugger is specified in the Kit.

[SPlatten]

@jsulm , no, no changes made between it displaying this state and then not showing it.