Hello, I ran the following:

guix gc -D $(guix build --no-grafts vice); guix build --no-substitutes
vice
guix challenge vice

The result of the last command was

/gnu/store/ixsr68sfkyfvp66mzg6291sv2gbdwvzc-vice-3.5 contents differ:
  local hash: 1gw2m26g506fivlki829h4ljjxs4s6c4c9hyi8bdzl1h4kw4qz6l
  
https://ci.guix.gnu.org/nar/lzip/ixsr68sfkyfvp66mzg6291sv2gbdwvzc-vice-3.5
: 0bsm4lf5pbfpq6q82jbvv0c9swpais572bf4lhbbrn2i9kld1krm
  differing files:
    /bin/xscpu64
    /bin/vsid
    /bin/x64sc
    /bin/xplus4
    /bin/x128
    /bin/xcbm5x0
    /bin/xvic
    /bin/xcbm2
    /bin/xpet

1 store items were analyzed:
  - 0 (0.0%) were identical
  - 1 (100.0%) differed
  - 0 (0.0%) were inconclusive

-- 
Christopher Howard
blog: https://librehacker.com
social: https://gnusocial.club/librehacker

On Wed, 2021-05-12 at 17:08 +0200, Brendan Tildesley wrote:
> guix gc -D $(guix build --no-grafts vice); guix build --no-
> substitutes vice