Re: binutils executables capture paths from build machine

[Steven Taschuk <steven@amotlpaa.org>]

Quoth Alexey Neyman:
> On 01/06/2018 11:27 AM, Steven Taschuk wrote:
> > I've understood correctly, the bash function do_binutils_for_host
> > configures binutils with --prefix=${CT_PREFIX_DIR} and installs the
> > executables with make install.  This procedure results in paths from
> > the build machine being embedded in the binaries, in at least two
> > places: the use of BINDIR at binutils-2.28/bfd/plugin.c:337; and
> > the various uses of DEBUGDIR in binutils-2.28/bfd/dwarf2.c (where
> > DEBUGDIR=${libdir}/debug; see binutils-2.28/bfd/configure.ac:108).
> 
> It is not just that. Also, NLS code embeds some build-time paths
> into the code, etc. [...]

I think in my situation, for binutils, it actually is just these
two spots.

(Details: My config has NLS disabled.  To handle debugging
information, I patch the build->host cross toolchain to support
BUILD_PATH_PREFIX_MAP from the Debian reproducible builds project.
I'm not sure what else you had in mind for "etc", but if I tweak
the binutils source in the two places I mentioned to use hard-coded
paths, the binutils executables become reproducible in my build,
in the few environments I've tested.  I won't be surprised to find
other irreproducibilities when I expand the set of build environments
that I test with, but that's where things stand right now.)

> [...] The problem is that we don't know where the
> toolchain will be located and many configure scripts "automagically"
> find headers/libraries based on the value of $prefix. [...]

Yeah, I understand that many packages are distributed with build
systems that don't support the build!=host case well, and that
magical autodetection in configure scripts is a big part of that, and
I certainly don't expect crosstool-ng to fix everybody else's build
systems.  As you said, that'd be a huge ongoing maintenance headache.

Is this known to be a problem with binutils specifically?

Also, if it is a problem with binutils, why does do_binutils_for_target
use the procedure where --prefix refers to a path on the host, and
DESTDIR is used to install it elsewhere on the build machine?

-- 
Steven Taschuk          http://www.amotlpaa.org/
"What? shall we receive good at the hand of God,
 and shall we not receive evil?"    -- Job 2:10