Notes for magicfilter - reproducible builds result

Version annotated: 1.2-64
Identified issues:
Identifier: random_order_in_md5sums
Description order of files in md5sums (in control.tar.gz) differ from build1 to build2. This only happens in
packages not using dh_md5sums and it's easily fixed by sorting the output of "find" before
piping it to md5sum. Example:
.
cd debian/tmp && \
find * -type f ! -regex "^DEBIAN/.*" -print0 |\
LC_ALL=C sort -z | xargs -0r md5sum > DEBIAN/md5sums
Identifier: gcc_captures_build_path
Description Captures build path, e.g., /build/1st/foo-42.0 v. /build/foo-42.0/2nd
Currently we vary the build path only when testing packages from unstable
and experimental, for stretch, buster and bullseye we recommend that rebuilds
are done in the same path as the original build.
.
dpkg-buildflags version 1.20.6+ sets -ffile-prefix-map by default
(and -fdebug-prefix-map in older versions) which fixes this issue
in many cases, but not all (see: records_build_flags).
.
There are patches submitted upstream to address this specific issue, but they
are unlikely to be merged at this point:
.
https://gcc.gnu.org/ml/gcc-patches/2017-04/msg00513.html
.
When this is accepted into GCC upstream, we could remove this note.
In the meantime, please do not remove this issue, nor mark it as deterministic,
nor untag these packages.
 

Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).