guix pull error

$ guix pull

Starting download of /tmp/guix-file.AyAoJq
From http://git.savannah.gnu.org/cgit/guix.git/snapshot/master.tar.gz...
 ….tar.gz                                   913KiB/s 00:12 | 11.0MiB transferred
Backtrace:
In guix/packages.scm:
 982: 19 [bag-grafts # #]
 966: 18 [fold-bag-dependencies #<procedure a7328f0 at guix/packages.scm:982:29 (package grafts)> ...]
 983: 17 [#<procedure a7328f0 at guix/packages.scm:982:29 (package grafts)> # ()]
 786: 16 [cache! #<weak-key-hash-table 936e040 0/223> # "i686-linux" ...]
 910: 15 [thunk]
 786: 14 [cache! #<weak-key-hash-table 936e260 167/223> # # ...]
1092: 13 [thunk]
1024: 12 [bag->derivation # # #]
In srfi/srfi-1.scm:
 578: 11 [map #<procedure a932270 at guix/packages.scm:1026:30 (t-1329587)> #]
In guix/packages.scm:
 846: 10 [expand-input # # # ...]
In guix/store.scm:
1249: 9 [run-with-store # ...]
In guix/packages.scm:
 480: 8 [#<procedure a9ecd50 at guix/packages.scm:480:2 (state)> #]
 485: 7 [#<procedure c1111a0 at guix/packages.scm:485:34 (state)> #]
In gnu/packages/bash.scm:
 249: 6 [#<procedure c1111c0 at gnu/packages/bash.scm:249:2 (state)> #]
In guix/download.scm:
 421: 5 [#<procedure b5b9528 at guix/download.scm:421:2 (state)> #]
In guix/store.scm:
1169: 4 [#<procedure a9f0fd8 at guix/store.scm:1168:28 (store)> #]
In guix/packages.scm:
 786: 3 [cache! #<weak-key-hash-table 936e260 167/223> #f ...]
1092: 2 [thunk]
 786: 1 [cache! #<weak-key-hash-table 936e0e0 169/223> #f ...]
 871: 0 [thunk]

guix/packages.scm:871:27: In procedure thunk:
guix/packages.scm:871:27: In procedure struct_vtable: Wrong type argument in position 1 (expecting struct): #f