Hi,

Lars-Dominik Braun <ldb@leibniz-psychology.org> skribis:

> I’m using guix on a multi-machine setup with a single remote guix-daemon that
> can be reached via SSH. Thus GUIX_DAEMON_SOCKET=ssh://master.<domain> on the
> compute nodes. Running `guix pull` on master works fine (the variable is not
> set here), but it does not on a compute node. Instead it fails with this error:
>
> ---snip---
> Backtrace:
>            1 (primitive-load "/gnu/store/n5wgvz287dwm62474mr42x34wl5j5wh7-compute-guix-derivation")
> In ice-9/eval.scm:
>    293:34  0 (_ #(#(#(#(#(#(#(#(#(#(#(#(#<directory (guile-user) 7f19dd213140> (?)) #) # ?) ?) ?) ?) ?) ?) ?) ?) ?) ?))
>
> ice-9/eval.scm:293:34: Throw to key `srfi-34' with args `(#<condition &store-connection-error [file: "/var/guix/daemon-socket/socket" errno: 111] 7f19dba3a090>)'.
> guix pull: error: You found a bug: the program '/gnu/store/n5wgvz287dwm62474mr42x34wl5j5wh7-compute-guix-derivation'
> failed to compute the derivation for Guix (version: "aac148a87b9a79b9992b8b1a9d76c217175d4a88"; system: "x86_64-linux";
> host version: "aac148a87b9a79b9992b8b1a9d76c217175d4a88"; pull-version: 1).
> Please report it by email to <bug-guix@gnu.org>.
> ---snap---
>
> Obviously the socket on that compute machine is not working, because it’s on an
> NFS share /var/guix belonging to master. But why is the socket considered in
> the first place?

This is a limitation in ‘build-aux/build-self.scm’:

      ;; Use the port beneath the current store as the stdin of BUILD.  This
      ;; way, we know 'open-pipe*' will not close it on 'exec'.  If PORT is
      ;; not a file port (e.g., it's an SSH channel), then the subprocess's
      ;; stdin will actually be /dev/null.
      (let* ((pipe   (with-input-from-port port
                       (lambda ()
                          ;; …
                                      (if (file-port? port)  ;<- here
                                          (number->string
                                           (logior major minor))
                                          "none"))))))

We could work around it by letting the ‘GUIX_DAEMON_SOCKET’ environment
variable through, along these lines: