[RFC PATCH v2 0/2] Improve native/cross reproducibility

[Jacob Kroon <jacob.kroon@gmail.com>]

This patch series is not intended for merge. I only send it out to
highlight where the problems are and to get some discussion going on
how/if we want to improve the sitation.

This is a patch series that tries to improve the reproducibility of the
native/cross binaries when building in different directories. This has
been tested on a Fedora 35 system which uses gcc 11.2.1 at the time of
writing.

The RUNTIME hack is questionable, maybe there is a better way to enforce
a fixed RUNTIME entry size during linking.

If in the end we do come up with a solution, then it should be tested on
the autobuilders, since otherwise this is going to degrade overtime. It
would then be important that the build paths are of significantly different
lengths. TMPDIR=/tmp/sysrootA/ and TMPDIR=/tmp/sysrootB/ will *not* uncover all
rpath problems.

Another thing that would be useful is if buildhistory could start
monitoring the depsig.do_populate_sysroot files, since that would highlight
changes in the actual file contents, which is currently not covered by
buildhistory.

The end result of this patch series is that I can build python3-native
in two different build paths, and the resuling sysroot-components/x86_64/
directories are identical, except for the 'fixmepath.cmd' files, which
are not included in the hash equiv. comparisons. Even so, there remains a lot of
native builds that are going to need to be fixed in similar ways as the
ones in this patch series.

Changes in v2:
 * Fixed building icedtea7-native/openjdk-8-native by prepending a '/'
   to the rpath padding
 * Squashed all the recipe-fixes together in one commit for now

Jacob

Jacob Kroon (2):
  bitbake.conf: Pad rpath and remove build ID in native binaries
  Improve native reproducibility in recipes

 meta/classes/chrpath.bbclass                  |  3 +
 meta/conf/bitbake.conf                        |  5 +-
 ...sysroot-and-debug-prefix-map-from-co.patch | 78 -------------------
 .../openssl/openssl/strip-buildinfo.patch     | 13 ++++
 .../openssl/openssl_3.0.0.bb                  | 10 +--
 meta/recipes-core/ncurses/ncurses.inc         |  4 +
 .../util-linux/util-linux_2.37.2.bb           |  2 +-
 .../libtool/libtool-native_2.4.6.bb           |  1 +
 ...ism.patch => perl-cross-determinism.patch} |  0
 .../perl-cross/perlcross_1.3.6.bb             |  4 +-
 meta/recipes-devtools/perl/perl_5.34.0.bb     |  5 ++
 .../pkgconfig/pkgconfig_git.bb                |  1 +
 .../python/python3/determinism.patch          | 15 ++++
 .../recipes-devtools/python/python3_3.10.0.bb |  8 ++
 14 files changed, 62 insertions(+), 87 deletions(-)
 delete mode 100644 meta/recipes-connectivity/openssl/openssl/0001-buildinfo-strip-sysroot-and-debug-prefix-map-from-co.patch
 create mode 100644 meta/recipes-connectivity/openssl/openssl/strip-buildinfo.patch
 rename meta/recipes-devtools/perl-cross/files/{determinism.patch => perl-cross-determinism.patch} (100%)
 create mode 100644 meta/recipes-devtools/python/python3/determinism.patch