**** BEGIN LOGGING AT Tue Apr 30 02:59:57 2019 Apr 30 14:16:33 i asked this on #ubuntu as well but they referred me here: so, i want to cross-compile some packages for arm64 from my amd64 system, so i added the http://ports.ubuntu.com repos, used sudo dpkg --add-architecture arm64, and ran sudo apt update. a good chunk of my dependencies install, but some of them, such as libopenmpi1.10 doesn't want to install in multiarch. what can i do about this? this on ubuntu 16.04 xenial. is it just a ma Apr 30 14:16:35 of using a newer version of ubuntu? i know the multiarch support was still fairly new back then. thanks! Apr 30 15:27:43 femtogram: what'S the error message? Apr 30 15:28:11 (and how are you installing it) Apr 30 15:30:18 tomreyn: i tried to install with sudo apt install libopenmpi1.10:arm64 but it then tries to remove libopenmpi1.10 (the native amd64 version) Apr 30 15:30:31 so no error message. just package conflict i believe Apr 30 15:31:03 i shoould probably have said: can you share the full output, on a pastebin? Apr 30 15:31:10 yes, absolutely Apr 30 15:31:29 great :) Apr 30 15:32:34 tomreyn: https://pastebin.ubuntu.com/p/WdHpRB6bBP/ Apr 30 15:32:48 thanks for looking into this! Apr 30 15:34:02 i should also mention i can install the arm64 versions of most packages without a problem. Apr 30 15:34:53 you did, but thanks for pointing it out again, i sometimes miss such hints. Apr 30 15:36:14 oh, sorry, i didn't realize i had already stated that! i should probably try to see if there are any other packages that are causing me trouble apart from openmpi. Apr 30 15:37:24 no worries! ;-) Apr 30 15:38:23 so, i wasn't aware of this particular package being unable to co-install. but this seems to be pretty much the same situation as discussed here https://unix.stackexchange.com/questions/252488/some-packages-cannot-be-installed-using-multi-arch-take-two Apr 30 15:39:19 okay, i guess what i was expecting. thank you for the help! Apr 30 15:39:34 femtogram: can you try to request installation of both the amd64 and arm64 package, and use --no-install-recommends Apr 30 15:40:05 i know the amd64 one is already installed, but this will make the resolver aware that you intend to keep both and it should try to find a solution for this Apr 30 15:40:46 that's sudo apt install --no-install-recommends libopenmpi1.10:arm64 libopenmpi1.10:amd64 Apr 30 15:41:54 also, do you actually need those libs or their dev packages? Apr 30 15:43:15 ah, it tries, but one of its dependencies seems to have the same problem. i tried to do the same thing with that dependency, which seems to just conflict: https://pastebin.ubuntu.com/p/hMKTzTCnYt/ Apr 30 15:43:55 right, so libibverbs1 is the actual package which is no co-installable Apr 30 15:44:25 ideally i would only need to use the dev packages, but i'm trying to build this stuff through ROS which doesn't distinguish between -dev and library packages Apr 30 15:44:43 ah, makes sense Apr 30 15:45:15 at this point i'm thinking the route i should take is just to use qemu. or i could also just install it into a chroot and use that yes? Apr 30 15:45:39 you may want to apt-mark auto libibverbs1 since apt just set libibverbs1 to be manually installed (since you specifiesd it as a particular package you'd want), when it was makred as automatically installed (as a dependency) previously. Apr 30 15:46:06 oh, doesn't matter too much. i'm doing all this stuff within a docker container anyway Apr 30 15:46:16 sbuild or (s)chroot should also work, yes. Apr 30 15:46:34 cool :) Apr 30 15:46:59 you also considered newer ubuntu versions, but they have newer openmpi library versions Apr 30 15:47:19 https://packages.ubuntu.com/search?keywords=libopenmpi&searchon=names Apr 30 15:47:32 yeah, i tried 19.04 right after i sent the original question actually. still has the same conflict. Apr 30 15:47:42 oh ok :-/ Apr 30 15:48:02 well, sometimes it's difficult, and this package only has community support Apr 30 15:49:04 yeah. i understand. it's okay, there are plenty of other approaches i can take :) i just thought multi-arch seemed like the right way to do so i wanted to see if i could make it work Apr 30 15:49:11 thank you for all the help! Apr 30 15:49:32 you're welcome ;-) Apr 30 15:50:43 ha! turns out on 19.04 that dependency was fixed, but it fails on a different one >.> Apr 30 15:50:59 (different dependency of libopenmpi that is) Apr 30 15:51:29 https://bugs.launchpad.net/ubuntu/+source/hwloc/+bug/1731719 Apr 30 16:02:36 hmm if what says is true you can just make the change suggested there. the bug report is about ubuntu 17.10, not 19.04, but it may well still be the same. Apr 30 16:08:37 https://wiki.debian.org/BuildingTutorial explains how to build a (modified) package. most steps you can skip, all you need is apt-get source PACKAGE + apt-get build-dep PACKAGE + dch -n (or edit the changelog manually, adding a new version) + DEB_BUILD_OPTIONS='nostrip noopt debug' dpkg-buildpackage -b -uc -us Apr 30 16:24:36 okay, i'll check if there is a newer bug report for 19.04 as well. thanks for the manual changing steps. i'm not sure if i want to deal with that because there are hundreds of dependencies and i would have to go through that with each of the packages that might have an issue. maybe it could be automated, but i think the qemu route is the simpler approach at that point Apr 30 16:29:07 may well be. note that i'm not a developer, so my experience with techniques and what's the better approach is very limited. Apr 30 16:29:28 you could also ask for suggestions / experiences in #ubuntu-devel / #ubuntu-app-devel Apr 30 16:30:52 ahh i see okay Apr 30 16:31:36 i'm not too concerned. the qemu approach should be pretty easy once i have it up and running and in a docker container. thanks again for all the help! **** ENDING LOGGING AT Wed May 01 02:59:57 2019