MacOS: attaching to namespace forbidden

[rjkroege]

Edwood is doing something wrong with names. I have tried to fix this with reattach-to-user-namespace but reliability is highly suspect.

[rjkroege]

On MacOS.

[rjkroege]

More details: on Catalina (occasionally) and now on Mac OS Big Sur, nothing can attach to Edwood's acme namespace. This breaks most interesting functionality (e.g. win, middle-clicking). p9p apps like plumber still successfully mount (and permit attach) via 9pserve. Conclusion: Edwood is doing something wrong with listening on socket connections. The exact error text is:

fsysmount: child: can't connect to acme: dial unix /tmp/ns.rjkroege.:0/acme: connect: connection refused

I had somewhat (naïvely?) assumed that this is related to the reattach-to-namespace... issues but this is not necessarily the case. (Note the differing situation with plumber.)

[fhs]

Edwood uses 9pserver to listen to the socket, same as p9p acme. Does p9p acme work?

Edwood runs 9pserve -lv /tmp/ns.rjkroege.:0/acme and speaks 9p via its stdin/stdout. The -l flag means it'll write to the log file /tmp/ns.rjkroege.:0/acme.log. What's in the log file?

[rjkroege]

Thanks for the pointer. 9pserve is crashing. It does so similarly for Acme. (It works for plumb though so I had initially discounted it.)

Sep 22 05:48:17.491 incoming call on /dev/fd/4
thread stack overflow: &t=700006fd8f58 tstk=7fbea0008000 n=256

Experiments

• Building with fhs/mux with go build -tags mux9p significantly improves Edwood operation but win still fails.

• I upgraded p9p to the most recent version. Acme including win then worked as expected.

• win also works with Edwood and the above linked p9p commit

• win doesn't work with Edwood built with -tags mux9p but other features do. That seems like a lower-priority issue. I will create a different issue to track this.

• I think libthread: use libc functions in ucontext for macOS is probably the most significant p9p change based on thread stack overflow

Summary

I deem this fixed enough to close this.