On Wed, Sep 28, 2022 at 7:09 AM Daniel P. Berrangé <berra...@redhat.com> wrote:
> On Wed, Sep 28, 2022 at 05:53:17AM -0400, Michael S. Tsirkin wrote: > > On Wed, Sep 28, 2022 at 10:37:14AM +0100, Daniel P. Berrangé wrote: > > > On Wed, Sep 28, 2022 at 05:26:42AM -0400, Michael S. Tsirkin wrote: > > > > On Tue, Jun 28, 2022 at 12:21:39PM +0200, Thomas Huth wrote: > > > > > On 28/06/2022 12.03, Michael S. Tsirkin wrote: > > > > > [...] > > > > > > For biosbits if we are going this route then I feel a submodule > is much > > > > > > better. It records which version exactly each qemu version > wants. > > > > > > > > > > As far as I know, you can also specify the version when using pip, > can't > > > > > you? So that's not really an advantage here. > > > > > > > > > > On the contrary, submodules have a couple of disadvantages that I > really > > > > > dislike: > > > > > > > > > > - submodules do not get updated automatically when doing a "git > checkout", > > > > > we have to update them via a script instead. This causes e.g. > trouble if you > > > > > rsync your source tree to a machine that has no access to the > internet and > > > > > you forgot to update the submodule before the sync > > > > > > > > > > - the content of submodules is not added to the tarballs that get > created on > > > > > the git forges automatically. There were lots of requests from > users in the > > > > > past that tried to download a tarball from github and then > wondered why they > > > > > couldn't compile QEMU. > > > > > > > > > > - we include the submodule content in our release tarballs, so > people get > > > > > the impression that hte submodule content is part of the QEMU > sources. This > > > > > has two disadvantages: > > > > > * We already got bug reports for the code in the submodule, > > > > > where people did not understand that they should report that > > > > > rather to the original project instead (i.e. you ship it - you > > > > > own it) > > > > > * People get the impression that QEMU is a huge monster > > > > > application if they count the number of code lines, run > > > > > their code scanner tools on the tarball contents, etc. > > > > > Remember "nemu", for example, where one of the main complaints > > > > > was that QEMU has too many lines of code? > > > > > > > > > > - If programs includes code via submodules, this gets a higher > > > > > burder for distro maintainers, since they have to patch each > > > > > and every package when there is a bug, instead of being able to > > > > > fix it in one central place. > > > > > > > > > > So in my opinion we should avoid new submodules if there is an > alternative. > > > > > > > > > > Thomas > > > > > > > > So looking at the latest proposals downloading files from CI, > > > > checksumming them etc etc. No auto checkout, not added automatically > > > > either, right? > > > > > > > > This seems to be the only difference: > > > > - we include the submodule content in our release tarballs > > > > > > That's just one of the issues with submodules. Working with them in > general > > > is not a pleasant experiance. > > > > This is what I asked about at the maintainers summit. > > I'd like to map the issues and see if there's anything > > we can do to solve them. In particular we will likely > > keep using submodules where we historically did > > so it's time well spent. > > > > I agree generally but the big question is what to replace these with. > > Below I assume the replacement is a script such as avocado or pytest > > with its own hashing, calling wget internally etc etc. > > > > > > > Thomas pointed out some of the issues, such > > > as 'git checkout' ignoring submodules, requiring extra steps to sync > them. > > > > > > Not different from a home grown SCM as part of test script, right? > > We're not building a home grown SCM as part of a test script, so > this answer is irrelevant. > > > > There's also the perenial problem that developers frequently send > > > patches that mistakenly include submodule changes, > > > > OK, so the thing to do would be to look for ways to exclude submodule > changes > > from git commits. > > If someone wants to make git suck less with submodules great, but needs > someone to actually do the work. > A big part of the problem is knowing which of the following commands I have to do to undo the uncommitted changes, the committed changes, the staged changes, etc: git submodule update --init --recursive git submodule update --init git submodule foreach --recursive git reset --hard git submodule foreach --recursive git clean -xfd git submodule foreach --recursive git clean -xfg (all of these are in my history, I honestly don't know the difference between the last two). And each 'oops' takes time away from upstreaming bsd-user I don't really have that much of. I've wasted hours on this over the past year between all the different ways it can screw up. To be fair, it is a relatively small fraction of the time, but as you can tell from the animation in my email it inspires much passion. Warner > > > I'd really like to see us doing more to eliminate as much use of > submodules > > > as is possible over time.p > > > > Or try to fix the problems, right? > > Again needs someone to actually make it happen. > > Meanwhile QEMU already has an integrated test harness in the form > of Avocado that does everything needed. If Avocado had just been > used for this biosbits test in the first place, the test would > likely have already been merged to QEMU, instead of us having this > never ending debate on how to re-invent an alternative to what > already avocado does. > > With regards, > Daniel > -- > |: https://berrange.com -o- > https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- > https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- > https://www.instagram.com/dberrange :| > > >
