linuxmaillists@xxxxxxxxxxx wrote: > What is EPOCH? Also why would autoupdate downgrade an > installed package? Same question, really... RPM always upgrades packages according to its idea of what the version number is. So normally, 1.2 would be an upgrade of 1.1. Sometimes, the packager wants things to go backwards. Usually, this is because a new version has bugs, and the packager wants to revert to the old version until things are fixed. Sometimes, it's because the package has changed its numbering scheme (say, from a date-based scheme to a release). An "epoch" is a way of getting around this. It's like a super-version number controlled by the packager, not the project. RPM insists that epochs should always increase: a package with an epoch of 1 will always be considered an upgrade to a package with an epoch of 0 or without an epoch. "Epoch" is English for "beginning of a new era in history; period marked by notable events". It carries the overtones of "the old order has passed away; this is the new order". Packages with an old epoch number or without one are considered as belonging to that old order of things, and no longer wanted, at least not if there is a new package available... (This also means that packagers have to be careful with the way they name their packages. Normally, 1.0-rc1 would be considered to be "later" to 1.0 by RPM, and hence an upgrade, whereas most programmers would consider 1.0-rc1 to be a "release candidate" or "not quite there" version of 1.0, and hence a downgrade. So you might have package-1.0.0-rc1 and eventually package-1.0.1...) Epochs are considered somewhat ugly, and are only used if there's no other real alternative. Hope this helps, James. -- E-mail: james@ | Say it with flowers, send a triffid. aprilcottage.co.uk |
