Hi Guix,
I'm tryng to set up offloading to a remote machine on a different network.
The preffered way to access machines on the remote network is via
openssh's ProxyJump option (as I understand it, this does some automated
port forwarding to access the eventual remote host via the proxy host). To
that end I've set up the following root ssh config in /root/.ssh/config:
```
Host proxy.remote.jackhill.us
User jackhill
Host builder.jackhill.us
User install
ProxyJump proxy.remote.jackhill.us
```
and /etc/guix/machines.scm:
```
(list
(build-machine
(name "builder.jackhill.us")
(systems '("x86_64-linux"))
(user "install")
(host-key "ssh-ed25519
AAAAC3NzaC1lZDI1NTE5AAAAIHls4Zn3WmWBdBCO43gmwJSd2afVzr980nQV4RLH/tw8 root@builder")
(private-key "/root/.ssh/id_ed25519")))
```
With this configuration `sudo -E guix offload test` suceeds:
```
$ sudo -E guix offload test
guix offload: testing 1 build machines defined in '/etc/guix/machines.scm'...
guix offload: Guix is usable on 'builder.jackhill.us' (test returned
"/gnu/store/883yjkl46dxw9mzykykmbs0yzwyxm17z-test")
guix offload: 'builder.jackhill.us' is running GNU Guile 3.0.5
guix offload: sending 1 store item (0 MiB) to 'builder.jackhill.us'...
exporting path `/gnu/store/xv5y6vb5rqivpgg8c23mmyifnbjx4zkg-export-test'
guix offload: 'builder.jackhill.us' successfully imported
'/gnu/store/xv5y6vb5rqivpgg8c23mmyifnbjx4zkg-export-test'
retrieving 1 store item from 'builder.jackhill.us'...
guix offload: successfully imported
'/gnu/store/0p7dz3ynp51qk4q9nvbscl5bv0hvfcsh-import-test' from
'builder.jackhill.us'
```
However, actually trying to build something that is not in my store fails:
```
$ guix build --no-substitutes okular
The following derivation will be built:
/gnu/store/gcbhh3rbpmcr4p4rdvsj9cw48gwkhnlf-okular-20.12.1.drv
process 18275 acquired build slot '/var/guix/offload/builder.jackhill.us:22/0'
guix offload: error: failed to connect to 'builder.jackhill.us': Socket error:
Connection reset by peer
waiting for locks or build slots...
^C
```
If I temporarily disable the need to use a proxy host and remove the ProxyJump
line from my ssh config, then it works as expected:
```
$ guix build --no-substitutes okular
The following derivation will be built:
/gnu/store/gcbhh3rbpmcr4p4rdvsj9cw48gwkhnlf-okular-20.12.1.drv
process 18551 acquired build slot '/var/guix/offload/builder.jackhill.us:22/0'
normalized load on machine 'builder.jackhill.us' is 0.01
building /gnu/store/gcbhh3rbpmcr4p4rdvsj9cw48gwkhnlf-okular-20.12.1.drv...
guix offload: sending 294 store items (286 MiB) to 'builder.jackhill.us'...
exporting path
`/gnu/store/36dq4d3dba7z2vjiqsqphndn7sb2wmyj-kconfig-5.70.0-guile-builder'
…
```
What am I doing wrong?
Best,
Jack
