Noticed this when testing guix system build with core-updates. Here's a
small example which reproduces the issue:


(use-modules (guix channels)
             (guix inferior))

(define channels
  (list (channel
         (name 'guix)
         (url "https://git.savannah.gnu.org/git/guix.git")
         (commit
          "e02c2f85b36ce1c733bd908a210ce1182bdd2560"))))

(define inferior
  (inferior-for-channels channels))

(first (lookup-inferior-packages inferior "linux-libre" "5.2.21"))


If you save that as a file then attempt to build it:


→ guix build -f test.scm 
Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'...
Backtrace:
           4 (primitive-load "/gnu/store/8mv5bpjgxg9c369xnbb5rf1kv9r?")
In ice-9/eval.scm:
    619:8  3 (_ #(#(#(#(#(#(#(#(#(#(#(?) ?) ?) ?) ?) ?) ?) ?) ?) ?) ?))
   182:19  2 (proc #(#(#(#(#(#(#(#(#(#(# ?) ?) ?) ?) ?) ?) ?) ?) ?) ?))
   142:16  1 (compile-top-call #<directory (guile-user) 7f1e0abc1f00> ?)
In unknown file:
           0 (%resolve-variable (7 . call-with-new-thread) #<directo?>)

ERROR: In procedure %resolve-variable:
Unbound variable: call-with-new-thread
guix build: error: You found a bug: the program '/gnu/store/8mv5bpjgxg9c369xnbb5rf1kv9r6z5hw-compute-guix-derivation'
failed to compute the derivation for Guix (version: "e02c2f85b36ce1c733bd908a210ce1182bdd2560"; system: "x86_64-linux";
host version: "a8cb1e72ef351330d1521833c1b270dcc0da593f"; pull-version: 1).
Please report it by email to <bug-guix@gnu.org>.