The unit suites had to install their toolchain on every run. The image
now carries the interpreters, so the make prerequisite finds them present.
The Composer vendor tree deliberately stays out of the image build: the
package cache is reached through the compose extra_hosts mapping, which
only exists for a running container, so a build-time composer install
would bypass the cache and talk to packagist directly. Fetching it from
the test target keeps it on the cached path.
test-unit-php and test-unit-ruby exited 0 whenever the interpreter or the
vendor tree was missing, so both suites were silently absent from every
gate. They now provision their toolchain through install-php/install-ruby
and fail loudly when that is impossible.
The three ensure_*_present helpers collapse into ensure_command_present
in system_pkg, and the ruby runner rejects an empty suite because
minitest reports success when nothing was required.
kevinveenbirkenbach