no matching pattern #<package polkit..

Hello Guix,

I obtained a latest dev ISO for guix system and tried installing it

just now. With the graphical installer, I received the error below for

two times. Perhaps it's a bug?

In ice-9/boot-9.scm:

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 `match-error' with args `("match" "no matching

pattern" #<package polkit@0.120 gnu/packages/polkit.scm: 54

7f6e64aa7b00>)'.

Command failed with exit code 1.

Press Enter to continue.

Thank you for all your work!

Best Regards,

Jin

Hey,

Thanks for the report.

I had the exact same issue while trying to build an installer

image. Running `make clean-go` and retrying fixed the error. Did you

build the installation image or downloaded it from the Guix website?

Thanks,

Mathieu

I downloaded it form the Guix website. If memory served me right, it was from

Jin

Hello everyone,

Someone reported the exact same issue today on IRC [1], with polkit

being the culprit. With a bigger backtrace, the match error happens at

line 901 in guix/gexp.scm, in the match inside the return part of

lower-inputs. This suggests that lower-object doesn't manage to return

a derivation but only the polkit package. I suspect that this has to do

with the complex polkit package interactions that we have, with polkit

being an identifier syntax for either polkit-mozjs or polkit-duktape,

with duktape package/inherit'ing polkit-mozjs with is itself replaced by

polkit-mozjs/fixed.

Maybe there's an interaction with the caching as well, while grafting

and looping?

I've tried to reproduce this locally by building a gexp that has either

polkit, polkit-duktape or polkit-mozjs as an input, enabling or

disabling fallback or grafting, to no avail.

Maybe someone else has another idea?

[1] https://logs.guix.gnu.org/guix/2022-04-22.log#154402

Best,

--

Josselin Poiret

severity 53594 important

quit

block 53214 by 53594

quit

Hi!

I hit this as well while running `guix system reconfigure'

(unfortunately I didn't capture the stack trace).

Re-running `guix system reconfigure' right after it had failed

worked...

So my guess is that it's a stateful issue, having to do with

grafts: if polkit is not in the store, then we build/download

it and fail right after that, which is why it succeeds the

second time.

To be continued...

Ludo'.

Hello,

The failing code is at gexp.scm:901:23, which corresponds to this:

(mlet %store-monad ((obj (lower-object thing system

#:target

(and (not native?)

target))))

901: (return (match obj

((? derivation? drv)

(derivation-input drv (list output)))

((? store-item? item)

item)

((? self-quoting?)

;; Some inputs such as <system-binding> can lower to

;; a self-quoting object that FILTERM will filter

;; out.

#f))))

That means (lower-object polkit) returned polkit (the package object)

instead of a derivation, hence ‘match-error’.

This is normally impossible: ‘lower-object’ calls ‘package->derivation’,

which returns a derivation. But maybe something weird is happening when

‘build-derivations’ aborts to the build-handler prompt, or when the

continuation is eventually resumed; maybe the object cache gets

“poisoned” with an incorrect value during that process.

So far the only reproducer we have seems to be along the lines of: grab

the ISO, run ‘guix pull’ (if it’s the 1.3.0 ISO; if it’s a fresh ISO,

that’s not necessary), run ‘guix system init’, watch it crash.

Does anyone have a simpler reproducer?

To be continued…

Ludo’.