Subject: Spooky problem in "nfs-root-os" system test

From: Danny Milosavljevic <[email-masked]>
Date: Sun, 13 Sep 2020 21:52:14 +0200

Hi,

I've got some spooky problem in the NFS root test (or in the VM setup by Guix,
really).

It seems to hang the system test in a part I cannot change (so it's not inside
the test script).

In order to reproduce, start with guix master commit
898fbb60b2354e82e5b7f259b44dbfed112a83aa--or any recent Guix master commit.

So far it's still "fine"-ish:

$ make TESTS="nfs-root-fs" check-system
[... works fine and eventually fails because port 20001 is waited for but is
never opened by the server--so far so good]

Now edit gnu/tests/nfs.scm to change

 ;(rpcmountd-port 20001)

to

 (rpcmountd-port 20001)

in order to fix the problem above--or so I thought.

$ make TESTS="nfs-root-fs" check-system
[... hangs in first VM--without even trying to start up the NFS server VM (as
far as I can tell)]

What is going on?  Also, how to debug this?

(same happens when enabling (rpcstatd-port 20002) only.
Also, doesn't rpcstatd have TWO ports--one to broadcast and one to listen?
How does one set up both using the operating-system configuration?)