Re: reproducible builds (bug report #43087)

[John W. Eaton]

On 08/27/2014 10:26 PM, Mike Miller wrote:
> On Wed, Aug 27, 2014 at 17:08:22 -0400, John W. Eaton wrote:

> > > It sounds like there are two main things you want to capture with the
> > > config.log. First, is this from some well-known official distribution,
> > > let's say, is this Octave as built by me or by foo. The second is how
> > > exactly was Octave built.
> >
> > Yes.
> >
> > > Well, if we know the first, we automatically know the second.
> >
> > I do if I still have the build around.  Which of course you could
> > argue I should if I'm distributing and supporting it.
>
> Or if you at least have the information needed to reproduce it :) For
> the case of mxe, maybe I'm wrong, but isn't that just the mxe hg
> revision and the command line used to build it? Isn't mxe completely
> self-bootstrapping / self-contained?

Ideally, yes.  And for Windows, I think everything is pretty much self 
contianed.  But I'm not sure we are completely there yet for "native" 
builds.  We don't build X11 or OpenGL (mesa?) libraries yet.  And for 
all systems, there may still be some build tools that we expect to get 
from the local system (make, for example, though there is also a script 
provided to download and build a given version of make for systems that 
don't have a recent enough version to handle the mxe-octave Makefiles). 
 So people may still get different results on different build systems. 
 I'd like to move toward eliminating those differences, but I think we 
still have some work to do.

> > > IOW are
> > > not the full contents of config.log mainly useful for getting
> > > information from people who build Octave themselves?
> >
> > Sure, that's also a reason that I'd like to be able to ask for
> > config.log, because I might want to help someone who is having trouble
> > even though they are using a binary that I didn't build.  Perhaps a
> > bug is discovered in their build that I haven't noticed but would like
> > to fix anyway and config.log might help me do that.
>
> Yeah, that use case makes complete sense. I guess I'm just wondering if
> we can separate the logging from the built Octave installer at some
> point in the future. Maybe it will just take some time and maturing of
> the process.

Yeah, config.log is far from the perfect collection of information, even 
for what I'm trying to use it for, but it can help, which is why I 
decided to start installing it.  I certainly wouldn't object to 
something better.

> I guess you're implying that if Octave defaulted to not install
> config.log, mxe-octave would still enable it anyway by default, so for
> mxe builds it would always be there. That's probably fair for now.

Yes.

jwe