On Tue, 31 Jan 2017 12:55:19 -0500, Bill Filler wrote: > On Tue, Jan 31, 2017 at 12:02 PM, Kyle Fazzari <kyle.fazz...@canonical.com> > wrote: > >> >> >> On 01/31/2017 08:40 AM, Didier Roche wrote: >> > Le 31/01/2017 à 17:18, Sergio Schvezov a écrit : >> >> On Tue, 31 Jan 2017 16:21:41 +0100, Olivier Tilloy wrote: >> >>> On Tue, Jan 31, 2017 at 2:12 PM, Timo Jyrinki >> >>> <timo.jyri...@gmail.com> wrote: >> >>>>> Do we have a clear understanding of why this happens? Qt apps are >> >>>>> supposed to be binary compatible against newer releases. >> >>>>> One exception could be if the app itself is shipping some plugins, >> >>>>> because in that case I believe that these plugins are somehow bound >> to a >> >>>>> specific Qt version. >> >>>> Yes, it seems snaps like ubuntu-terminal-app and dekko ship their on >> >>>> Qt version which should not be the case when the platform snap is >> >>>> used. >> >>> This is a bit tricky: when packaging a Qt application that uses the >> >>> platform snap, snapcraft will use ldd to crawl the app’s binaries and >> >>> will automagically add the libraries that it depends on to the >> >>> resulting snap (those libs are taken from the host system). >> >> This will be disabled by default and snapcraft will error on missing >> libraries >> >> unless you tell it is ok. >> >> >> > (first, sorry for the bad control+enter on my previous email) >> > >> > I'm a little bit uncomfortable with that statement for mainly 2 reasons: >> > * Changing default behavior is always cumbersome to developers who just >> > wants to work on their app. Here, we are introducing a breaking change >> > (snaps that used to build won't build anymore, especially those on >> > core). It's annoying also for people who did hook up their CI to >> > autopublish a snap. >> > >> > This is why we need to justify and carefully explain the change, in a >> > clear, defined way. I would suggest coordinating with David for a blog >> > post that we promote here and on the developer website: >> > 1. Why are we changing this? -> we are not doing this just to bother >> > you, developer, here is the technical reason why we are doing it. >> > 2. A small and minimal snippet of code of before/after so that people >> > aren't lost and know what to do >> > 3. When is it going to be released. Version, date, upgrade process. >> > >> > As this default behavior changes a lot of things, we need to ensure as >> > well that all our code snippet and tutorials are updated. So >> > coordinating all the way, please! >> >> I completely agree. >> >> > * The second one is that it seems there is a disable mechanism, mainly >> > telling "I know what I'm doing". I think this isn't what we want to >> > achieve and it's not fine-grained enough. >> >> Without knowing much about this change, I figure something like this >> would fit into build-attributes, which is per-part at least. >> >> > A common use-case I can see is an app depending on a platform snap and >> > embedding additional libraries for some functionality. If we have to >> > disable the check for not erroring out on the platform snap libs, we may >> > miss, on snap creation, or upgrade or more… additional library checks. >> > It seems we shouldn't use a big hammer like this (if it's really what >> > I'm understanding from this statement), but rather trying to get a way >> > more fine-grained and precise approach. >> >> You mean like asking the snap developer to provide an explicit list of >> libraries to error on? Or an explicit list of libraries to pull from the >> system if missing? Anything more fine-grained sounds messy to maintain >> from a snap developer perspective. And this applies to either direction: >> automatically pulling in dependencies from the system, or erroring on >> missing libraries. >> >> Note that, in your example, the consumer app should likely be built with >> the providing snap unpacked into the staging area. This guarantees that >> the consumer is build with the libraries etc. actually contained in the >> providing snap. Using this workflow, snapcraft doesn't do anything >> special with the libs contained in the staging area, even if they're >> filtered out of the final snap via the `prime` keyword. Where "anything >> special" is defined as trying to pull them in from the system, etc. I >> figure the "error on missing libs" would follow the same logic, and not >> error if the libs are satisfied in stage. >> > > From a developers perspective, it would be great if a workflow like the > following could happen: > - if my snap uses other snaps via content-sharing, the providing snaps > would be automatically unpacked during the build and used to satisfy > depends so the libs are not copied into my snap
This is why I told the SDK team to build a "release tarball" of whatever their framework is, with this people would just `after` it and it would just work. This will avoid the need for adding build packages equivalent to those of whatever that snap provides or for you guys to depend on a PPA to be able to build. > - if missing lib errors occur, give me the option to ignore and use system > libs, or error-out with the list of missing deps This is planned. > This would satisfy use cases where the providing snap contains all the libs > my snap needs or just a portion of them. Sounds like we have most of this > already in some form but not exactly.. Right. Also, this is just planned, but the details and execution haven't been finalized given that I haven't discussed with everyone. -- Sent using Dekko from my Ubuntu device -- Snapcraft mailing list Snapcraft@lists.snapcraft.io Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/snapcraft
