I just got this running guix pull building guix-system-tests. looks 
kinda related to your patch since it mentions local-file



[  6/ 54] loading...	 22.2% of 27 filesrandom seed for tests: 1601620953
[ 10/ 54] loading...	 37.0% of 27 filesBacktrace:
In ice-9/eval.scm:
     163:9 19 (_ #(#(#<directory (gnu tests install) 7fffeda39640>) #<<operating-system> kernel: #<package linux-libre@5.8.12 gnu/packages/linux.scm:721 7fffe91d3c80> kernel-loadable-modules: ()?> ?))
    173:47 18 (_ #(#(#(#<directory (gnu tests install) 7fffeda39640>) #<<operating-system> kernel: #<package linux-libre@5.8.12 gnu/packages/linux.scm:721 7fffe91d3c80> kernel-loadable-module?> ?) ?))
     159:9 17 (_ #(#(#(#<directory (gnu tests install) 7fffeda39640>) #<<operating-system> kernel: #<package linux-libre@5.8.12 gnu/packages/linux.scm:721 7fffe91d3c80> kernel-loadable-module?> ?) ?))
     159:9 16 (_ #(#(#(#<directory (gnu tests install) 7fffeda39640>) #<<operating-system> kernel: #<package linux-libre@5.8.12 gnu/packages/linux.scm:721 7fffe91d3c80> kernel-loadable-module?> ?) ?))
    293:34 15 (_ #(#(#<directory (gnu tests install) 7fffeda39640>) #<<operating-system> kernel: #<package linux-libre@5.8.12 gnu/packages/linux.scm:721 7fffe91d3c80> kernel-loadable-modules: () ?>))
In srfi/srfi-1.scm:
    586:29 14 (map1 (#<<service> type: #<service-type virtual-terminal 7fffe95c6300> value: #t> #<<service> type: #<service-type kmscon 7fffe95d4d00> value: #<<kmscon-configuration> kmscon: #<pa?> ?))
    586:29 13 (map1 (#<<service> type: #<service-type kmscon 7fffe95d4d00> value: #<<kmscon-configuration> kmscon: #<package kmscon@0.0.0-1.01dd0a2 gnu/packages/terminals.scm:256 7fffeac0d320> v?> ?))
    586:29 12 (map1 (#<<service> type: #<service-type login 7fffe95c6240> value: #<<login-configuration> motd: #<<plain-file> name: "motd" content: "\n\x1b[1;37mWelcome to the installation of GN?> ?))
    586:29 11 (map1 (#<<service> type: #<service-type documentation 7fffe68542c0> value: "tty2"> #<<service> type: #<service-type configuration-template 7fffe6854180> value: #t> #<<service> type?> ?))
    586:29 10 (map1 (#<<service> type: #<service-type configuration-template 7fffe6854180> value: #t> #<<service> type: #<service-type mingetty 7fffe95c61c0> value: #<<mingetty-configuration> mi?> ?))
    586:29  9 (map1 (#<<service> type: #<service-type mingetty 7fffe95c61c0> value: #<<mingetty-configuration> mingetty: #<package mingetty@1.08 gnu/packages/admin.scm:701 7fffe931bdc0> tty: "tt?> ?))
    586:29  8 (map1 (#<<service> type: #<service-type mingetty 7fffe95c61c0> value: #<<mingetty-configuration> mingetty: #<package mingetty@1.08 gnu/packages/admin.scm:701 7fffe931bdc0> tty: "tt?> ?))
    586:29  7 (map1 (#<<service> type: #<service-type mingetty 7fffe95c61c0> value: #<<mingetty-configuration> mingetty: #<package mingetty@1.08 gnu/packages/admin.scm:701 7fffe931bdc0> tty: "tt?> ?))
    586:29  6 (map1 (#<<service> type: #<service-type mingetty 7fffe95c61c0> value: #<<mingetty-configuration> mingetty: #<package mingetty@1.08 gnu/packages/admin.scm:701 7fffe931bdc0> tty: "tt?> ?))
    586:29  5 (map1 (#<<service> type: #<service-type syslog 7fffe95c6140> value: #<<syslog-configuration> syslogd: #<file-append #<package inetutils@1.9.4 gnu/packages/admin.scm:598 7fffe931bf0?> ?))
    586:17  4 (map1 (#<<service> type: #<service-type guix 7fffe95c6040> value: #<<guix-configuration> guix: #<package guix@1.1.0-27.1c21468 gnu/packages/package-management.scm:135 7fffead81e60>?> ?))
In ice-9/eval.scm:
    196:43  3 (_ #(#(#(#<directory (gnu tests install) 7fffeda39640>) #<<service> type: #<service-type guix 7fffe95c6040> value: #<<guix-configuration> guix: #<package guix@1.1.0-27.1c21468 gn?>) #))
    293:34  2 (_ #(#(#(#<directory (gnu tests install) 7fffeda39640>) #<<service> type: #<service-type guix 7fffe95c6040> value: #<<guix-configuration> guix: #<package guix@1.1.0-27.1c21468 gn?>) #))
In gnu/packages/package-management.scm:
    549:20  1 (_)
In guix/gexp.scm:
     405:0  0 (%local-file _ _ _ #:literal? _ #:location _ #:recursive? _ #:select? _)

guix/gexp.scm:405:0: In procedure %local-file:
Invalid keyword: "guix-current"