bug#56012: guix pull fails. cannot build guix-package-cache.drv.

[vidak]

hey all.

vidak here.

i cannot get `guix pull` to work for me.

i am having issues getting the package-cache.drv to build.

i was homeless, and unable to update my workstation for about... a
month?

here are some related issues:

https://issues.guix.gnu.org/52650

https://issues.guix.gnu.org/47949

https://issues.guix.gnu.org/33661

i can trace the output logs to this commit, which seems to be the
offending one. 

commit -- 3b50b327f7cf3226a0e37bc6afa1e921c9c075f7

```
~ $ cat
/var/log/guix/drvs/zk/1hgixlv3gccgbriad7nr2xyla8bbzx-guix-package-cache.drv
(repl-version 0 1 1)
Generating package cache for
'/gnu/store/1mzdd7rf9r34xiibcs1gpjsf7jkh6a0r-profile'...
(exception unbound-variable (value #f) (value "Unbound variable: ~S")
(value (libpng-1.2)) (value #f))
```

i can `guix pull --commit` to before 31-05-2022, but i cannot seem to
pull to anything later than that date.

can anyone help me?

thanks so much in advance.

~vidak

https://zoinks.one/vidak