tests/__init__.py keeps a run offline, its scratch under tmp/ and its
installer cache its own, but only discover -s tests -t . imported it.
discover tests ran with RETROBIOS_OFFLINE unset, scratch on the /tmp
tmpfs and the user's real installer cache, the setting in which e2e
fixtures had written into the shared .cache/large. Every test module now
imports the package first, and a test fails on a module that does not.
test_verify_listing.py took its line with the previous commit.
The site test modules were cut by review pass (test_site_r2_css to test_site_r5_wiki): the passes of one subject become one module, and the modules that stood alone take the name of what they hold. The installer test classes named after a review take the name of what they test. One test left --manifest set for the tests after it, which the new order showed: it now resets the sources.
Abdessamad Derraz