Andrew Savchenko posted on Sun, 24 Jul 2016 00:30:39 +0300 as excerpted: > Do we ever had such case like multiple versions of the same > single-slotted package installed or recorded as installed in the real > world? I'm not sure even in this, but I may assume that it may happen > one day. > > Do we have any proof that PM can recover from such situation, > where VDB is a mess and installed files can also be a mess? I'm not sure > in this at all. > > Do we have any test suits for portage (as the most popular PM > implementation) for such cases? I doubt this, I can find none. I'm not > sure if such tests are implemented in other PM test suits too.
Think of how a package is upgraded (by portage, I don't know enough about the others to describe the process for them). The package is built, then installed to a temporary location, then "qmerged" from the temporary location to the live filesystem, replacing the previous version's files and recording the new one in the installed-package database, then the old version is unmerged and its record removed from the installed-package database. What happens if there's a crash in either the qmerge or old-version unmerge steps? Right, now there's parts of two versions in the installed-package database, and who knows what files from each on the live filesystem. I'm not a portage dev so won't comment on the test suite angle, but portage has been able to handle this with the user simply redoing the upgrade (whether from binpkg or full rebuild) for many years now (singe before I became a gentooer in 2004, I know as I had some faulty hardware at the time and regularly crashed during build and installs, which was likely before REPLACING_VERSIONS was a thing), and given the number of installations out there and the stress of parallel-building some packages while others are installing, the code to handle this is GOING to get regularly tested. This needs to continue to work, thus the PMS rules, and ebuilds that are unprepared to deal with it aren't going to help. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman
