* build-aux/run-system-tests.scm (source-commit): New procedure.
(tests-for-current-guix): Add 'commit' parameter and pass it to
'channel-source->package'.
(run-system-tests): Call 'source-commit' and pass the result to
'tests-for-current-guix'.
* gnu/ci.scm (channel-build-system)[build, lower]: Honor #:source.
(channel-source->package): New procedure.
(system-test-jobs): Remove 'instance' and call to
'checkout->channel-instance'. Use 'channel-source->package'.
* build-aux/run-system-tests.scm (tests-for-channel-instance): Rename to...
(tests-for-current-guix): ... this. Change 'instance' to 'source'.
(run-system-tests): Use 'local-file' instead of 'interned-file' for
SOURCE.
This is a followup to 7e6d8d366a.
It means that "make check-system" can run tests from (gnu tests install)
much faster because it does not need to build a full 'guix' package.
* gnu/ci.scm (channel-instance->package): Export.
* build-aux/run-system-tests.scm (tests-for-channel-instance): New
procedure, with code formerly in 'run-system-tests'.
(run-system-tests): Call 'interned-file' for SOURCE, and add call to
'tests-for-channel-instance'.
* gnu/tests.scm (<system-test>): New record type.
(write-system-test, test-modules, fold-system-tests)
(all-system-tests): New procedures.
* gnu/tests/base.scm (%test-basic-os): Turn into a <system-test>.
* gnu/tests/install.scm (%test-installed-os): Likewise.
* build-aux/run-system-tests.scm (%system-tests): Remove.
(run-system-tests): Use 'all-system-tests'.
Ludovic Courtès