<div dir="ltr">For beam and beam.smp there is a define, ERLANG_COMPILE_DATE, set that holds the compile date for debugging purposes. It it used when generating an erl_crash.dump or for etp when viewing core (it reads a global symbol) files.<div><br></div><div>You can turn off ERLANG_COMPILE_DATE usage with configure option: --disable-saved-compile-time</div><div><br></div><div>// Björn-Egil</div><div><br></div>
</div><div class="gmail_extra"><br><div class="gmail_quote">2016-06-09 19:31 GMT+02:00 Pjotr Prins <span dir="ltr"><<a href="mailto:pjotr.public12@thebird.nl" target="_blank">pjotr.public12@thebird.nl</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<br>
<br>
We noticed the great improvement in the recent release of Erlang, but<br>
there are still some problems. Leo found the following:<br>
<br>
<br>
----- Forwarded message from Leo Famulari <<a href="mailto:leo@famulari.name">leo@famulari.name</a>> -----<br>
<br>
Date: Tue, 24 May 2016 12:07:10 -0400<br>
From: Leo Famulari <<a href="mailto:leo@famulari.name">leo@famulari.name</a>><br>
To: Pjotr Prins <<a href="mailto:pjotr2016@thebird.nl">pjotr2016@thebird.nl</a>><br>
Subject: Re: [v3] Erlang<br>
User-Agent: Mutt/1.6.0 (2016-04-01)<br>
<br>
Sort of! The compiler does reproducibly build the attached<br>
helloworld.erl.<br>
<br>
But, the Erlang package itself does not build repeatedly. I've attached<br>
the diffoscope report (in HTML format) of two build iterations from my<br>
machine.<br>
<br>
Basically, there are still timestamps in 'lib/erlang/erts-8.0/bin/beam'<br>
and it's neighbour, 'beam.smp'.<br>
<br>
There are also a variety of files that include lines like:<br>
"%%%·This·file·was·automatically·generated·by·snmpc_mib_to_hrl·version·5.2.3<br>
%%%·Date:·24-May-2016::15:33:12"<br>
<br>
I remember finding the code that generates these lines and thinking it<br>
should not be too hard for us to patch. I could crudely replace the<br>
timestamp generator with "1", or an Erlang programmer could make it<br>
respect SOURCE_DATE_EPOCH.<br>
<br>
Or, should we contact Erlang to see if they can fix these issues before<br>
the final release?<br>
<br>
On Tue, May 24, 2016 at 03:44:08PM +0200, Pjotr Prins wrote:<br>
> Does it work?<br>
><br>
> On Mon, May 23, 2016 at 02:59:14PM -0400, Leo Famulari wrote:<br>
> > On Mon, May 23, 2016 at 01:48:11PM +0200, Pjotr Prins wrote:<br>
> > > Good news. The changelog for<br>
> > ><br>
> > > <a href="http://erlang.org/download/OTP-19.0-rc1.README" rel="noreferrer" target="_blank">http://erlang.org/download/OTP-19.0-rc1.README</a><br>
> > ><br>
> > > says that<br>
> > ><br>
> > > OTP-13504 Application(s): compiler<br>
> > ><br>
> > > The compiler will no longer put the compilation date<br>
> > > and time into BEAM files. That means that two BEAM<br>
> > > files compiled on the same computer from the same<br>
> > > source code and compilation options will be identical.<br>
> > ><br>
> > > Note: If you want to find out whether a BEAM file on<br>
> > > disk is different from the loaded code, compared the<br>
> > > MD5 value obtained from Mod:module_info(md5) with the<br>
> > > MD5 value obtained from beam_lib:md5(BeamFileForMod)`<br>
> > ><br>
> > > This means that Erlang and Elixir may go into GNU Guix :)<br>
> ><br>
> > Indeed, great news :) I will try building it with Guix today.<br>
> ><br>
><br>
> --<br>
<br>
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</blockquote></div><br></div>