Subject: r-readr in a container has got no timezone data

From: Wiktor Żelazny <[email-masked]>
Date: Tue, 18 Feb 2020 16:19:26 +0100

Related to [1]. Reproducing:

   guix environment -C --pure --ad-hoc r r-readr
   Rscript -e 'library(readr); default_locale()'

A hack that fixes this issue is to include tzdata among the environment
inputs, and to set

   TZDIR=/gnu/store/$(ls -F /gnu/store | grep tzdata.*/ | head -n 1)share/zoneinfo

(actually, one needs also coreutils and grep to do that, but that’s
beyond the point). I haven’t tried it (yet?), but maybe it suffices to
add tzdata to r-readr inputs in the package definition to fix this
issue.

WŻ

[1]: https://github.com/tidyverse/readr/issues/952