The problem is that this opens a debugger port on the Next app launcher process, not on the actual server. The Next app launcher binary (bin/next) only spawns the server process and then sits around waiting for its termination.

In Next docs, it’s mentioned that inspect flag must pe passed via NODE_OPTIONS env variable. In this case, Next extracts it from there, increment the port number by 1, and then launches the server process with it.

I was able to connect to that +1 port then, but unfortunately, the breakpoints do not work still: it sounds like this is not a real server process, it’s (again) some turbopack related launcher process or something (at least in the list of source files available in the debugger, there are only chunks from .next/build folder, not from .next/server or so). I could not make it work yet.