Backtrace:
In guix/packages.scm:
 309: 19 [cache # "x86_64-linux" #<procedure thunk ()>]
 384: 18 [thunk]
In srfi/srfi-1.scm:
 578: 17 [map #<procedure 2701b40 at guix/packages.scm:385:39 (t-215469)> #]
In guix/packages.scm:
 346: 16 [expand-input # # # ...]
 309: 15 [cache # "x86_64-linux" #<procedure thunk ()>]
 384: 14 [thunk]
In srfi/srfi-1.scm:
 578: 13 [map #<procedure 274c000 at guix/packages.scm:385:39 (t-215469)> #]
In guix/packages.scm:
 346: 12 [expand-input # # # ...]
 309: 11 [cache # "x86_64-linux" #<procedure thunk ()>]
 384: 10 [thunk]
In srfi/srfi-1.scm:
 578: 9 [map #<procedure 2762690 at guix/packages.scm:385:39 (t-215469)> #]
In guix/packages.scm:
 361: 8 [expand-input # # # ...]
In guix/download.scm:
 189: 7 [url-fetch # "mirror://gnu/gmp/gmp-5.1.2.tar.xz" sha256 ...]
In guix/packages.scm:
 309: 6 [cache # "x86_64-linux" #<procedure thunk ()>]
 396: 5 [thunk]
In gnu/packages/bootstrap.scm:
 169: 4 [build # "guile-bootstrap-2.0" #f ...]
In guix/store.scm:
 478: 3 [#<procedure 2228440 at guix/store.scm:468:4 (server basename recursive? hash-algo file-name)> # ...]
 461: 2 [add-to-store # "tar" #t ...]
In guix/nar.scm:
 148: 1 [dump "/home/amirouche/.config/guix/latest/gnu/packages/bootstrap/x86_64-linux/tar"]
  79: 0 [write-contents "/home/amirouche/.config/guix/latest/gnu/packages/bootstrap/x86_64-linux/tar" ...]

guix/nar.scm:79:8: In procedure write-contents:
guix/nar.scm:79:8: In procedure module-lookup: Unbound variable: sendfile