Thanks to klibc being fixed, rootskel finally built in the archive and hence we've now finally enabled the daily builds of debian-installer for s390x. They're still untested, though, and I hope to come around to that in the near future.
In other news I've spent some more time chasing weird 64bit big endian issues in glib. Newer versions have regressed in their support and again assume that certain fields are either 32bit/64bit little endian or 32bit big endian, which is unhelpful. Sadly the testsuite is guilty as well, which doesn't make debugging any easier. I still suspect a bug in either gio or GClosure's interface to libffi, let's hope that when that one's found that the remainder of the archive is building just fine… (Currently a lot is blocking on glib-networking which fails in its testsuite. And of course there are still usertagged bugs that need to be fixed.)
It would be cool if we could run more testsuites during package building and find the bugs in them. glib does have one, but its failures are non-fatal for the build (also because there are so many failures). That would make porting to future architectures a tad easier.