Subject: Re: bug#40125: Problem with guix offload: Remote channel closed

From: Ludovic Courtès <[email-masked]>
Date: Sun, 22 Mar 2020 21:45:57 +0100

Hello!

Mikael Djurfeldt <[email-masked]> skribis:

> This error message is more common. In this case, I couldn't see anything
> obviously strange except the following backtrace which contains strange
> characters:
>
> 31963 write(2, "Backtrace:\n          13 (apply-smob/1 #<catch-closure
> 56464c2232a0>)\nIn ice-9/boot-9.scm:\n    718:2 12 (call-with-prompt
> (\"prompt\") #<procedure 56464c2407e0 \342\200\246> \342\200\246)\nIn
> ice-9/eval.scm:\n    619:8 11 (_ #(#(#<directory (guile-user)
> 56464c2c4750>)))\nIn ice-9/command-line.scm:\n   181:18 10 (_ #<input:
> string 56464c2d2bd0>)\nIn unknown file:\n           9 (eval (begin
> (use-modules (guix) (srfi srfi-34) # #) \342\200\246) #)\nIn
> ice-9/eval.scm:\n   721:20  8 (primitive-eval (begin (use-modules (guix)
> (srfi \342\200\246) \342"..., 1150 <unfinished ...>

We’re missing a tiny bit.  :-)  Could you run strace with ‘-s 3000’ or
similar so that it doesn’t truncate it?

(The “strange characters” are Unicode HORIZONTAL ELLIPSIS.)

> I have also noticed that the above (the error message) happens inside the
> function send-files. It is the last error clause at the end of the function
> which reports the error message.
>
> I'd like to be able to, e.g., modify the function send-files to give some
> debugging output. How can I easily do that? Should I checkout guix with git
> and try to run it in the source tree? Or do you have other suggestions?

Note that the problems happens on the remote machine, which is what
makes it harder to debug.

If you want to debug (guix ssh), you’ll then have to run the daemon from
your Git checkout to exercise that code:

  sudo -E ./pre-inst-env guix-daemon --build-users-group=guixbuild

HTH!

Ludo’.