Calibre isn't displaying any text in its book view interface (see 
screenshot). Even after I delete all the calibre configuration files in 
.config and .local/share the problem persists. I do not know if this is 
specific to guix or a problem generally with Calibre  5.36.

~$ guix describe
Generation 47    Feb 19 2022 17:42:44    (current)
   guix f8aa889
     repository URL: https://git.savannah.gnu.org/git/guix.git
     branch: master
     commit: f8aa8899e265a46fd3dff6c717ec484057ba2b68

This is the case when calibre is run in the following ways (with the 
cache and configs deleted in between):
~/guix-home/profile/bin/calibre

~/guix-profile/bin/calibre

guix shell calibre -- calibre

guix shell --pure calibre -- calibre

guix time-machine -- shell calibre -- calibre

-- 
-Jesse Gibbons