The test was failing with ENOSPC.
* gnu/tests/docker.scm (run-docker-system-test)[vm]: Increase 'memory-size'.
(%test-docker-system): Change 'locale-libcs' for the OS passed to
'system-docker-image'.
This helps find the (json) module in the virtual machine.
* gnu/tests/docker.scm (build-tarball&run-docker-test,
run-docker-system-test): Replace guile-2.2 with guile-3.0.
The system image would no longer fit in memory, starting from commit
8c7eb58453.
* gnu/tests/docker.scm (run-docker-system-test): Set 'memory-size' to 3500.
Fixes <https://bugs.gnu.org/37161>.
* guix/scripts/pack.scm (docker-image)[build]: Add a 'directory' entry
for "/tmp" to DIRECTIVES.
* tests/pack.scm ("docker-image + localstatedir"): Test the presence of /tmp.
* gnu/tests/docker.scm (run-docker-test)["Load docker image and run
it"]: Test the presence and permission bits of "/tmp".
* guix/docker.scm (config): Add #:environment parameter and honor it.
(build-docker-image): Likewise, and pass it to 'config'.
* guix/scripts/pack.scm (docker-image): Import (guix profiles) and (guix
search-paths). Call 'profile-search-paths' and pass #:environment to
'build-docker-image'.
* gnu/tests/docker.scm (run-docker-test)["Load docker image and run it"]:
Add example that expects (json) to be available.
* gnu/tests/docker.scm (build-tarball&run-docker-test): Replace
%BOOTSTRAP-GUILE by GUILE-2.2 and GUILE-JSON in the environment.
* guix/scripts/pack.scm (self-contained-tarball): Add #:entry-point and
warn when it's true.
(squashfs-image): Add #:entry-point and honor it.
(docker-image): Add #:entry-point and honor it.
(%options, show-help): Add '--entry-point'.
(guix-pack): Honor '--entry-point' and pass #:entry-point to BUILD-IMAGE.
* gnu/tests/docker.scm (run-docker-test): Test 'docker run' with the
default entry point.
(build-tarball&run-docker-test): Pass #:entry-point to 'docker-image'.
* doc/guix.texi (Invoking guix pack): Document it.
* gnu/tests/singularity.scm (run-singularity-test)["singularity run"]:
New test.
(build-tarball&run-singularity-test): Pass #:entry-point to
'squashfs-image'.
This simplifies use of images created with 'guix system docker-image'.
* gnu/system/vm.scm (system-docker-image)[boot-program]: New variable.
[os]: Add it to the GC roots.
[build]: Pass #:entry-point to 'build-docker-image'.
* gnu/tests/docker.scm (run-docker-system-test): New procedure.
(%test-docker-system): New variable.
* doc/guix.texi (Invoking guix system): Remove GUIX_NEW_SYSTEM hack and
'--entrypoint' from the example. Mention 'docker create', 'docker
start', and 'docker exec'.
* gnu/tests/docker.scm (run-docker-test): Add parameters. Load and run
docker container. Check response of guest guile.
(build-tarball&run-docker-test): New procedure.
(%test-docker): Use it.
[description]: Modify.
