Hi Nige, On 1 June 2016 at 11:33, Nigel Verity <nigelver...@hotmail.com> wrote: > I've recently gone over to 64bit Ubuntu versions on all my boxes and this > raised a question. Does every binary object in the repositories have to be > compiled twice - once for 32 and again for 64bit architectures
Yes. Take a random app like chromium in 16.04:- http://packages.ubuntu.com/search?keywords=chromium http://packages.ubuntu.com/xenial/chromium-browser Note there's a 32-bit (i386) build:- http://packages.ubuntu.com/xenial/i386/chromium-browser/download ..and a 64-bit (amd64) build:- http://packages.ubuntu.com/xenial/amd64/chromium-browser/download Both were compiled separately on different machines in the Launchpad build farm. https://launchpad.net/~canonical-chromium-builds/+archive/ubuntu/stage/+build/9739028 " Successfully built on lgw01-02 Started on 2016-05-13 Finished on 2016-05-14 (took 7 hours, 28 minutes, 11.8 seconds)" https://launchpad.net/~canonical-chromium-builds/+archive/ubuntu/stage/+build/9739030 "Successfully built on lgw01-48 Started on 2016-05-13 Finished on 2016-05-13 (took 6 hours, 32 minutes, 4.7 seconds" as well as a build for armhf. https://launchpad.net/~canonical-chromium-builds/+archive/ubuntu/stage/+build/9739029 " Successfully built on kishi08 (highbank) Started on 2016-05-13 Finished on 2016-05-14 (took 12 hours, 20 minutes, 34.6 seconds)" Maybe, in the future chromium will build on an aarch64 (64-bit arm) machine too :) > - or can > 32bit compilations run on a 64bit host? > That works too! Skype for example is a good example of a 32 bit (i386) app which runs on 64 bit (amd64) machines. However it's possible to install 32-bit versions of apps from the archive on a 64-bit machine, should you need to, just suffix :i386 on the end:- sudo apt install foo:i386 > If they are separate versions is there a likelihood that some particularly > obscure packages will fall by the wayside simply through being considered > not worth compiling for 64bit? Perhaps there is a formal policy on this. > No, we monitor things with FTBFS (Fail to build from source) and correct those issues. In fact it's more likely these days to be the other way round, in that some things build on 64-bit but don't build for 32-bit, as some newer packages are 64-bit only for whatever reason. If a package is available in one arch and not the other, generally it's a bug - known or not. Cheers, Al. -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/
