bug#45537: Update fails with this error

[znavko]

Hi! Please, repair this.

$ guix pull && guix package-u
...
building /gnu/store/ccp139yzx1wzlh1dln4gi93wlvzl2pzc-guix-610cd6a17.drv...
building CA certificate bundle...
building fonts directory...
building directory of Info manuals...
building database for manual pages...
building profile with 1 package...
building /gnu/store/dj670bvqzchf2xjhy2hnc52i1faxa11d-inferior-script.scm.drv...
building package cache...
-builder for `/gnu/store/b2dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv' failed to produce output path `/gnu/store/mnailki8gsw9k6y9x5mi9qc4vva400dy-guix-package-cache'
build of /gnu/store/b2dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv failed
View build log at '/var/log/guix/drvs/b2/dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv.bz2'.
cannot build derivation `/gnu/store/i1r62qfdhlshbszbz5fhd7s21g9wiv6f-profile.drv': 1 dependencies couldn't be built

$ cp /var/log/guix/drvs/b2/dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv.bz2 .
$ bzip2 -d -k -v dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv.bz2
$ cat dkxxh10w1nsilsg2xhvvhhq8sdbmi2-guix-package-cache.drv
(repl-version 0 1 1)
Generating package cache for '/gnu/store/4xv2dib26yqlrg3367nlnwph5m1lh72w-profile'...
(exception unbound-variable (value #f) (value "Unbound variable: ~S") (value (r-snpstats)) (value #f))

$ guix describe
Generation 3 Dec 26 2020 15:37:12 (current)
guix 4969b51
repository URL: https://git.savannah.gnu.org/git/guix.git
branch: master
commit: 4969b51d175497bfcc354c91803e9d70542b7113