bug#46383: docker 19.03.13 build failure on guix master

[Danny Milosavljevic]

=== SKIP: registry TestMirrorEndpointLookup (0.01s)
    registry_test.go:668: os.Getuid() != 0: skipping test that requires root

=== SKIP: volume/local TestCreateWithOpts (0.00s)
    local_test.go:182: os.Getuid() != 0: requires mounts


=== Failed
=== FAIL: pkg/signal TestCatchAll (0.02s)
    signal_linux_test.go:38: assertion failed: urgent I/O condition (string) != 
child exited (string)

DONE 1941 tests, 75 skipped, 1 failure in 212.409s
command "hack/test/unit" failed with status 1

$ LC_ALL=C sudo guix describe
  guix 703e5c9
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 703e5c92eeb38d86455c2b1cace5cad9fc08b349

pgpxCX_m_tKnH.pgp
Description: OpenPGP digital signature