test-manual: document LTO related reproducibility bug

(From yocto-docs rev: 33b6f7cec780f77ed9cd0518f72ec8c0e3c08e68)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Reviewed-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/documentation/test-manual/reproducible-builds.rst b/documentation/test-manual/reproducible-builds.rst
index e13583c0bf..c66c82f86a 100644
--- a/documentation/test-manual/reproducible-builds.rst
+++ b/documentation/test-manual/reproducible-builds.rst
@@ -68,6 +68,17 @@ things we do within the build system to ensure reproducibility include:
 -  Filtering the tools available from the host's ``PATH`` to only a specific set
    of tools, set using the :term:`HOSTTOOLS` variable.
 
+.. note::
+
+   Because of an open bug in GCC, using ``DISTRO_FEATURES_append = " lto"`` or
+   adding ``-flto`` (Link Time Optimization) to ``CFLAGS`` makes the resulting
+   binary non-reproducible, in that it depends on the full absolute build path
+   to ``recipe-sysroot-native``, so installing the Yocto Project in a different
+   directory results in a different binary.
+
+   This issue is addressed by
+   :yocto_bugs:`bug 14481 -  Programs built with -flto are not reproducible</show_bug.cgi?id=14481>`.
+
 =========================================
 Can we prove the project is reproducible?
 =========================================