substitute: updating list of substitutes from 'https://mirror.hydra.gnu.org'...   1.1%Backtrace:
substitute: In ice-9/boot-9.scm:
substitute:  160: 9 [catch #t #<catch-closure 155aa00> ...]
substitute: In unknown file:
substitute:    ?: 8 [apply-smob/1 #<catch-closure 155aa00>]
substitute: In ice-9/boot-9.scm:
substitute:   66: 7 [call-with-prompt prompt0 ...]
substitute: In ice-9/eval.scm:
substitute:  432: 6 [eval # #]
substitute: In ice-9/boot-9.scm:
substitute: 2412: 5 [save-module-excursion #<procedure 157b900 at ice-9/boot-9.scm:4084:3 ()>]
substitute: 4089: 4 [#<procedure 157b900 at ice-9/boot-9.scm:4084:3 ()>]
substitute: 1734: 3 [%start-stack load-stack ...]
substitute: 1739: 2 [#<procedure 158db40 ()>]
substitute: In unknown file:
substitute:    ?: 1 [primitive-load "/gnu/store/nqy9m6hhnkkfwr5wyq5bac96v9s9hc9i-guix-0.12.0-9.25a4/bin/.guix-real"]
substitute: In guix/ui.scm:
substitute: 1255: 0 [run-guix-command substitute "--query"]
substitute: 
substitute: guix/ui.scm:1255:8: In procedure run-guix-command:
substitute: guix/ui.scm:1255:8: Throw to key `bad-response' with args `("Bad Response-Line: ~s" (""))'.
guix system: error: build failed: substituter `substitute' died unexpectedly