Re: Meson build

On Tue, Sep 01, 2020 at 03:13:39PM +0200, Ján Tomko wrote: > On a Tuesday in 2020, Pavel Hrdina wrote: > > On Sun, Aug 30, 2020 at 02:34:56AM +0200, Toolybird wrote: > > > Hi, > > > > > > Just a heads up on my experiences with the new build system. > > > > > > Arch Linux > > > meson-0.55.1 > > > > > > Overall, it looks good, so well done! > > > > > > Just a couple of minor things I noted: > > > > > > 1. Arch uses a meson wrapper script (arch-meson) that sets: > > > > > >   --buildtype plain > > > > > > This seems to trigger a bug in meson that results in copious bogus compiler warnings: > > > > > > cc1: warning: ‘-Wformat-y2k’ ignored without ‘-Wformat’ [-Wformat-y2k] > > > cc1: warning: ‘-Wformat-extra-args’ ignored without ‘-Wformat’ [-Wformat-extra-args] > > > cc1: warning: ‘-Wformat-zero-length’ ignored without ‘-Wformat’ [-Wformat-zero-length] > > > cc1: warning: ‘-Wformat-contains-nul’ ignored without ‘-Wformat’ [-Wformat-contains-nul] > > > cc1: warning: ‘-Wformat-security’ ignored without ‘-Wformat’ [-Wformat-security] > > > > > > which of course breaks -Werror builds. > > > > > > I can easily work around it by setting `-D git_werror=disabled' or even better still: > > > > > > CFLAGS+=" -Wall" arch-meson... > > > > This should be easily fixable by adding -Wformat in our list of flags > > that we pass to compiler. We were incorrectly relying on meson to add > > -Wformat automatically and since we add the other -Wformat* flags > > manually we should add -Wformat as well. I'll post a patch to fix this. > > > > What would that fix? > > It would neither be a plain build, nor a full -Werror build (since we're > missing -Wall). It would fix building libvirt from git in case user uses buildtype=plain.

> > > Maybe this github issue is related?: > > > > > > https://github.com/mesonbuild/meson/issues/7399 > > > > > > 2. Arch currently builds libvirt with support for ZFS. Seeing as ZFS is not in the distro proper, a simple Autoconf tweak is used: > > > > > > ZFS=/usr/bin/zfs ZPOOL=/usr/bin/zpool \ > > > ./configure ... > > > > > > This is surprisingly hard to emulate with meson, in fact it appears impossible, unless I resort to dodgy hacks with sed etc. > > > > I'm not sure I understand the reasoning behind this. > > > > For normal usage users of libvirt should not fake that something exists > > to make libvirt building the support for it because obviously it will > > not work. > > > > If you are asking from packager POV you should add ZFS as regular build > > dependency and also run dependency. > > > > If it's possible to fake it, it's not a build dependency. > > Jano > > > I'm looking into the arch linux packaging and if that's your concern I > > guess you should create libvirt-storage-zfs sub-package like it is done > > for gluster, iscsi-direct and rbd. > > > > Pavel > >