-The lesson here is that with the existance of (any of) the usrmerge and the debootstrap default change, "merged `/usr`" Debian systems exist already, and that packages built on such directory schemes
+The lesson here is that with the existance of (any of) the usrmerge and the debootstrap default change, "merged `/usr`" Debian systems exist already, and that packages built on hosts with such directory schemes can _potentially_ be broken on non-"merged `/usr`" systems. At this point, the two variants have to be supported, at least as installation targets of Debian packages.
+
+Two initiatives are worth mentioning at this point:
+* [a patch](https://lists.debian.org/20181202212535.GC11687@gaara.hadrons.org) has been proposed for dpkg to mark packages built on "merged `/usr`" with a `Build-Tainted-By: merged-usr-via-symlinks`;
+* the reproducible builds team has added a "merged `/usr`" variation to their setup, and have then [tagged](https://tests.reproducible-builds.org/debian/issues/unstable/paths_vary_due_to_usrmerge_issue.html) the Debian packages from unstable which had differences due to "merged `/usr`". It seems that ~61 packages were affected by differing builds; 32 from these have been fixed in unstable already.