Previously, under Cuirass, we'd add "build-aux/cuirass/../hydra/../..".
But then, commit c45477d2a1 added this
in (gnu system vm):
(local-file (search-path %load-path
"guix/store/schema.sql"))
Since 'search-path' would not return an absolute file name, 'local-file'
would try to resolve that relative to "gnu/system", leading to:
ERROR: In procedure force:
In procedure canonicalize-path: No such file or directory: "/gnu/store/…-guix-ce573b1/gnu/system/build-aux/cuirass/../hydra/../../guix/store/schema.sql
* build-aux/hydra/gnu-system.scm <top level>: Canonicalize DIR before
adding it to %LOAD-PATH.
7b0449712e