guest@gnu ~$ guix system reconfigure /run/current-system/configuration.scm 
guix system: warning: cannot determine provenance for current system
Updating channel 'guix' from Git repository at '/home/ludo/src/guix/+version-1.4.0/'...
SWH: found revision 989a3916dc8967bcb7275f10452f89bc6c3389cc with directory at 'https://archive.softwareheritage.org/api/1/directory/9752db1e8f2001dc33dcdcf14f27bab79594c041/'
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/HEAD
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/branches/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/config
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/description
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/hooks/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/info/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/info/exclude
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/info/refs
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/info/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/info/packs
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/pack/
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/pack/pack-a5edcd8b43d9945205899808da8eeb53203479bb.idx
swh:1:rev:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/pack/pack-a5edcd8b43d9945205899808da8eeb53203479bb.pack
Backtrace:
In guix/gexp.scm:
   299:22 19 (_ _)
In guix/store.scm:
   1998:8 18 (_ _)
In guix/packages.scm:
  1914:11 17 (_ _)
In guix/build-system/channel.scm:
     42:2 16 (_ _)
In guix/store.scm:
  2042:38 15 (_ #<store-connection 256.99 7f09f27cec30>)
In guix/channels.scm:
    532:7 14 (loop _ _)
In guix/combinators.scm:
    48:26 13 (fold2 #<procedure 7f09f0627840 at guix/channels.scm:5…> …)
In guix/channels.scm:
   542:29 12 (_ #<<channel> name: guix url: "/home/ludo/src/guix/+v…> …)
   413:17 11 (latest-channel-instance #<store-connection 256.99 7f0…> …)
In guix/git.scm:
   475:29 10 (update-cached-checkout _ #:ref _ #:recursive? _ # _ # _ …)
    376:2  9 (_ git-error #<<git-error> code: -1 message: "unsupport…>)
In guix/utils.scm:
    954:8  8 (call-with-temporary-directory _)
In guix/git.scm:
   378:10  7 (_ "/tmp/guix-directory.flcZc1")
In guix/swh.scm:
    655:8  6 (call-with-temporary-directory _)
   682:11  5 (_ "/tmp/guix-directory.keGuFS")
In guix/build/utils.scm:
  1018:28  4 (_)
In unknown file:
           3 (get-bytevector-n! #<input: string 7f09f0cd6cb0> # 0 #)
In web/response.scm:
     95:2  2 (read! _ _ _)
In ice-9/boot-9.scm:
  1685:16  1 (raise-exception _ #:continuable? _)
  1685:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
Throw to key `bad-response' with args `("EOF while reading response body: ~a bytes of ~a" (203717490 281006080))'.
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: swh\:1\:rev\:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects/pack: Cannot utime: No such file or directory
tar: swh\:1\:rev\:989a3916dc8967bcb7275f10452f89bc6c3389cc.git/objects: Cannot utime: No such file or directory
tar: swh\:1\:rev\:989a3916dc8967bcb7275f10452f89bc6c3389cc.git: Cannot utime: No such file or directory
tar: Error is not recoverable: exiting now