$ guix time-machine 8e7e414aa998fe8c0de8a491c91aab8b8d9c58f4 -- graph maven
Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'...
Computing Guix derivation for 'x86_64-linux'...  Backtrace:
In ice-9/boot-9.scm:
  3393:24 19 (_)
   222:29 18 (map1 _)
   222:29 17 (map1 _)
   222:29 16 (map1 _)
   222:29 15 (map1 _)
   222:29 14 (map1 _)
   222:17 13 (map1 (((gnu packages crates-io)) ((gnu packages crates-graphics)) ((gnu packages documentation)) (#) ?))
  3297:17 12 (resolve-interface (gnu packages crates-io) #:select _ #:hide _ #:prefix _ #:renamer _ #:version _)
In ice-9/threads.scm:
    390:8 11 (_ _)
In ice-9/boot-9.scm:
  3223:13 10 (_)
In ice-9/threads.scm:
    390:8  9 (_ _)
In ice-9/boot-9.scm:
  3507:20  8 (_)
   2806:4  7 (save-module-excursion _)
  3527:26  6 (_)
In unknown file:
           5 (primitive-load-path "gnu/packages/crates-io" #<procedure 7f340025f540 at ice-9/boot-9.scm:3514:37 ()>)
In ice-9/eval.scm:
    619:8  4 (_ #f)
   626:19  3 (_ #<directory (gnu packages crates-io) 7f33fa906c80>)
    159:9  2 (_ #<directory (gnu packages crates-io) 7f33fa906c80>)
   223:20  1 (proc #<directory (gnu packages crates-io) 7f33fa906c80>)
In unknown file:
           0 (%resolve-variable (7 . skim-0.7) #<directory (gnu packages crates-io) 7f33fa906c80>)

ERROR: In procedure %resolve-variable:
error: skim-0.7: unbound variable
-guix time-machine: error: You found a bug: the program '/gnu/store/3sfsx0lzx3n9dhsdrd4vxriz0avi4j6l-compute-guix-derivation'
failed to compute the derivation for Guix (version: "453f18db343cbad1892186b85c7eb07f364b399e"; system: "x86_64-linux";
host version: "838347207cdd96de1ad0127aaf4b2c378c7c2148"; pull-version: 1).
Please report it by email to <bug-guix@gnu.org>.