Question about mkfs.erofs and reproducible builds

[Gao Xiang]

On Wed, Oct 27, 2021 at 04:40:28PM +0300, Todor Ivanov wrote:
>    Hi, Gao,
> 
>    Indeed c_version:[1.3-g9fe440d0], seems to fix the problem :) Thank you
> very much for the prompt and accurate feedback! Do you think we can use the
> dev branch for our images or is it better until it is merged into master?
> What do you think?

Many thanks for your feedback too in time! ;)
I'm fine to fast-forward the main branch without bumping up the version
(since other folks also needed that as well...)

But I'd like to postpone new erofs-utils v1.4 for a while since I'm
waiting for merging some other on-going features too~

Thanks,
Gao Xiang

> 
> Kind regards,
> Todor
> 
> 
> On Wed, Oct 27, 2021 at 2:51 PM Gao Xiang <hsiangkao at linux.alibaba.com>
> wrote:
> 
> > On Wed, Oct 27, 2021 at 02:41:54PM +0300, Todor Ivanov wrote:
> > >     Hi, Gao,
> > >
> > >     This is how I installed mkfs.erofs on debian10:
> > >
> > > apt-get install pkg-config liblz4-dev gawk
> > > wget
> > >
> > http://ftp.debian.org/debian/pool/main/e/erofs-utils/erofs-utils_1.3.orig.tar.gz
> > > tar xvzpf erofs-utils_1.3.orig.tar.gz
> > > cd erofs-utils-1.3/
> > > ./autogen.sh
> > > ./configure
> > > make
> > > make install
> > >
> > > Can you tell me where do I clone it from and if build instructions are
> > > different?
> >
> > You could get the latest dev branch from:
> > git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git -b dev
> >
> > We fixed some reproducable build issues recently, I think it might
> > be related to
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git/commit/?id=6324fac820c28c6a946f595fa58a0abba0f48eb4
> >
> > Thanks,
> > Gao Xiang
> >
> > >
> > > Kind regards,
> > > Todor
> > >
> > > On Wed, Oct 27, 2021 at 2:27 PM Gao Xiang <hsiangkao at linux.alibaba.com>
> > > wrote:
> > >
> > > > Hi Todor,
> > > >
> > > > On Wed, Oct 27, 2021 at 02:11:24PM +0300, Todor Ivanov wrote:
> > > > >         Hello,
> > > > >
> > > > >         We are trying to replace squashfs with erofs and face an
> > issue
> > > > with
> > > > > reproducing the build from one and the same source folder. The source
> > > > > folder is "/etc" actually taken from an offline ubuntu 20.04 image
> > and
> > > > > mounted as read-only.
> > > > >         I managed to narrow down the scope and it turns out that the
> > > > issue
> > > > > is when you have a file starting with "." (dot) in this folder. I.e.:
> > > > >
> > > > > etc/.anyfilename
> > > > >
> > > > > If I remove this file the erofs image of "etc" is reproducible (-T
> > and -U
> > > > > are used as well)
> > > > >
> > > > > The issue is somehow related to the other 76 subfolders of etc and
> > this
> > > > > file starting with dot. For example if I create such .anyfilename in
> > usr
> > > > or
> > > > > var, there is no issue. Also if I create this file under
> > > > > etc/xdg/.anyfilename, this is fine as well.
> > > > > I also tried with etc from debian10 and the result is the same.
> > Removing
> > > > > any file that starts with dot directly under etc, makes the erofs
> > build
> > > > > reproducible.
> > > > > Do you have any advice on this?
> > > >
> > > > In principle filenames starting with '.' won't impact anything about
> > > > reproducible builds...
> > > >
> > > > Let me investigate it now... But may I ask which erofs-utils version
> > > > is used? Does it still happen on the latest dev branch?
> > > >
> > > > Thanks,
> > > > Gao Xiang
> > > >
> > > > >
> > > > > Regards,
> > > > > Todor
> > > >
> >