This morning I ran my usual daily update and was presented with a long list of kde-app packages, including KMail-2. The only problem was four blocks that portage couldn't sort out on its own, so I evicted the existing versions with emerge -C and continued.
Then kleopatra failed to build, as in bug 602924. The fix there worked (I should call it an evasion really) and kleopatra built ok. Then, on continuing with emerge -uaDvU, another whole load of blocks arose, mostly from portage trying to pull back in the versions of packages that had just been superseded. There seemed to be no way out of that, so I took my sledge-hammer and started an emerge -e world. No blocks were reported, so I think I might be getting away with it. I'm about half-way through so far, and I'm writing this via webmail. So, tread warily, anyone who is offered 16.12.0 versions of 148 kde-apps packages. -- Regards, Peter