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From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: reproducible builds and debugging information
Date: Tue, 24 Mar 2015 22:09:50 +0100
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Tom=C3=A1=C5=A1 =C4=8Cech <sleep_walker@gnu.org> skribis:

> As I was tracing curl code, I needed to rebuild the package with
> "-ggdb" in CFLAGS and enable debug among outputs.
>
> The later doesn't change the hash (and the generated code), but the
> first does.

Both approaches change the output hash.  (As soon as a bit changes in
the build process, the output hash changes.)

Adding a =E2=80=9Cdebug=E2=80=9D output is nice because we have support to =
automatically
DTRT (info "(guix) Installing Debugging Files").

> So I'd like to propose to put "-ggdb" to generally applied CFLAGS for
> whole distribution.

Packages that have an autoconf-based build system, and I suppose most
others, are built with -g.  The binaries get stripped by default and
debugging info is lost unless the package has a =E2=80=9Cdebug=E2=80=9D out=
put.

Currently a few key packages have that, but most don=E2=80=99t (I think Deb=
ian
does something similar, not sure about other distros.)

We could make it opt-out rather than opt-in, but the issue is disk usage
on build machine (including end-user machines.)  See
<http://lists.gnu.org/archive/html/bug-guix/2013-07/msg00015.html>.

Thoughts?

Ludo=E2=80=99.