From time to time I get the following error, the only thing I change is
IPv6 config in static-networking service.  Sometimes it fails, but after
a few more attempts with the same config it deploys sucessfully.

--8<---------------cut here---------------start------------->8---
-*- mode: compilation; default-directory: "~/work/abcdw/trop.in/" -*-
Compilation started at Tue Oct  4 14:19:46

make -k deploy-pinky
guix deploy ./guix/pinky.scm
The following 1 machine will be deployed:
  pinky

guix deploy: deploying to pinky...
guix deploy: sending 0 store items (0 MiB) to '23.137.249.202'...
guix deploy: sending 0 store items (0 MiB) to '23.137.249.202'...
substitute: updating substitutes from 'https://substitutes.nonguix.org'... 100.0%
substitute: updating substitutes from 'https://bordeaux.guix.gnu.org'... 100.0%
substitute: updating substitutes from 'http://ci.guix.trop.in'... 100.0%
The following derivations will be built:
  /gnu/store/yzilvx4jr4s7174f6azxxbb5c24311xc-remote-exp.scm.drv
  /gnu/store/sqlbbg5z19h2ww86p8nzhfbnidsm5sag-switch-to-system.scm.drv
  /gnu/store/ayssizgz8i4mnk6p2yhilqgzwim4ql7j-system.drv
  /gnu/store/9fxf3gcgi07hg5nmhjvnvlhk6829h304-provenance.drv
  /gnu/store/djs7vabv5wr3inz3pva87wfw7ya10ajq-boot.drv
  /gnu/store/smmzsd1b9v4qmncvl0pl6f0nrasp39ks-activate.scm.drv
  /gnu/store/5hpm7v0xnqqilhj7qdg66cjkf8dvkimx-activate-service.scm.drv
  /gnu/store/g62yd6a8wd081w0y4jji83dbcxhiks3i-etc.drv

building /gnu/store/9fxf3gcgi07hg5nmhjvnvlhk6829h304-provenance.drv...
building /gnu/store/g62yd6a8wd081w0y4jji83dbcxhiks3i-etc.drv...
building /gnu/store/5hpm7v0xnqqilhj7qdg66cjkf8dvkimx-activate-service.scm.drv...
building /gnu/store/smmzsd1b9v4qmncvl0pl6f0nrasp39ks-activate.scm.drv...
building /gnu/store/djs7vabv5wr3inz3pva87wfw7ya10ajq-boot.drv...
building /gnu/store/ayssizgz8i4mnk6p2yhilqgzwim4ql7j-system.drv...
building /gnu/store/sqlbbg5z19h2ww86p8nzhfbnidsm5sag-switch-to-system.scm.drv...
building /gnu/store/yzilvx4jr4s7174f6azxxbb5c24311xc-remote-exp.scm.drv...
guix deploy: sending 10 store items (0 MiB) to '23.137.249.202'...
guix deploy: sending 0 store items (0 MiB) to '23.137.249.202'...
guix deploy: sending 0 store items (0 MiB) to '23.137.249.202'...
The following derivations will be built:
  /gnu/store/36rmj2xp0sd7lx0ndv8imkyxrh2lmmdy-remote-exp.scm.drv
  /gnu/store/823hs0g4wxdmfwmj6nn8smcnrp45a1g7-install-bootloader.scm.drv
  /gnu/store/0m7f6gg0d0iq6r99p40rw3m65z52fjiy-grub.cfg.drv

building /gnu/store/0m7f6gg0d0iq6r99p40rw3m65z52fjiy-grub.cfg.drv...
building /gnu/store/823hs0g4wxdmfwmj6nn8smcnrp45a1g7-install-bootloader.scm.drv...
building /gnu/store/36rmj2xp0sd7lx0ndv8imkyxrh2lmmdy-remote-exp.scm.drv...
;;; [2022/10/04 14:20:23.191118, 0] [GSSH ERROR] Channel opening failure: channel 67 error (2) open failed: #<input-output: channel (closed) 7f7d1af9e140>
Backtrace:
In guix/store.scm:
  1402:13 19 (map/accumulate-builds #<store-connection 256.99 7f7d1…> …)
  1377:11 18 (map/accumulate-builds #<store-connection 256.99 7f7d1…> …)
   1295:8 17 (call-with-build-handler #<procedure 7f7d15629ea0 at g…> …)
In ice-9/boot-9.scm:
  1752:10 16 (with-exception-handler _ _ #:unwind? _ # _)
In guix/scripts/deploy.scm:
    168:6 15 (_)
In guix/store.scm:
  2165:25 14 (run-with-store #<store-connection 256.99 7f7d143b0690> …)
In gnu/machine/ssh.scm:
   506:32 13 (_ _)
In ice-9/boot-9.scm:
  1752:10 12 (with-exception-handler _ _ #:unwind? _ # _)
In gnu/machine/ssh.scm:
   506:32 11 (_)
In guix/store.scm:
  2165:25 10 (run-with-store #<store-connection 256.99 7f7d1207b3c0> …)
In guix/remote.scm:
   138:10  9 (_ _)
In guix/store.scm:
  2037:38  8 (_ #<store-connection 256.99 7f7d1207b3c0>)
In guix/ssh.scm:
    376:2  7 (send-files #<store-connection 256.99 7f7d1207b3c0> _ # …)
    222:5  6 (remote-run (begin (use-modules (guix) (srfi #) # #) …) #)
In ssh/popen.scm:
     64:4  5 (open-remote-pipe* _ "r+" _ . _)
In unknown file:
           4 (channel-open-session #<input-output: channel (closed) …>)
In ice-9/boot-9.scm:
  1685:16  3 (raise-exception _ #:continuable? _)
  1683:16  2 (raise-exception _ #:continuable? _)
  1685:16  1 (raise-exception _ #:continuable? _)
  1685:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
Throw to key `guile-ssh-error' with args `("channel-open-session" "Channel opening failure: channel 67 error (2) open failed" #<input-output: channel (closed) 7f7d1af9e140> #f)'.
make: *** [Makefile:28: deploy-pinky] Error 1

Compilation exited abnormally with code 2 at Tue Oct  4 14:20:23
--8<---------------cut here---------------end--------------->8---

-- 
Best regards,
Andrew Tropin