Hi, I think the correct place for adding the dependency on nss_nis is actually ypbind, where it was present until the rpm was removed from glibc. Now that it is once again packaged (separately) I will add it back.
No need for a bugzilla now, since I was already made aware of this issue but for the future it is definitely better to create one instead of commenting on an already stable update.
Please note that pushing this update will force everyone already on -21 to rebuild their libdb environments regardless of whether they did or did not encounter the segfault when applying the fixes as opposed to forcing only those people that are affected by the bug to rebuild...
DB_VERSION_MISMATCH errors are expected as libdb refuses to access its environment when there differences between the old and new environment (due to libdb upgrade) and it cannot safely rebuild it (as is the case with accessing rpmdb from scriplets)