Ansgar Burchardt writes: > There were discussions about enabling this by default years ago, I > don't think minor issues should be a reason to delay this change. > > Note that it has been delayed for after the stretch release as there > were major issues back then (it was enabled by default for a short time > in stretch). It took >5 months for someone to find a problem this time > which is pretty good for any change.
So, I went through all reproducible build failures in unstable without notes and added notes for differences caused by building in merged-/usr vs non-merged-/usr packages. Together with what other people tagged, about 60 problems were found. (The oldest rebuild result for unstable is 17 days old, the merged-/usr variation was deployed before that[1].) [1] https://bugs.debian.org/901473#43 There might be some more that as diffoscope had problems or the diff was too large for some packages (but I'll assume that in this case merged-/usr is not the only problem the package had). This should cover all packages that had no other problems and were reproducible before, that is about 80% of the archive. Assuming the rate is similar for packages which have other reproducible build problems, I would expect 60 / 80*20 = 15 more problems. I haven't looked at build failures, but I would expect these to be usually not caused by merged-/usr. So an estimated ~80 packages which might need adjustments for building correctly in both merged-/usr and non-merged-/usr. I guess less than for the average new release of GCC ;-) The problems are usually easy to fix by passing an explicit path the the package's configure script at build time; of course there might be some package where it is more complicated. Ansgar