While working on upgrading the toolchain from GCC 11.2 to 11.3, we found that we needed to advance the v4 validation commit to v6.1.0-alpha. Unfortunately, those builds failed with clang because the most recent upgrade to libunwind throws new errors on the ZAP platforms when built with clang. Amazon Linux 2022, Ubuntu 22.04, and RHEL 9 failed compiling Boost at src/third_party/boost/boost/thread/pthread/thread_data.hpp:61:19 due to a sign comparison warning whenever PTHREAD_MIN_STACK_SIZE is defined. Finally, we disabled LLVM builds on static hosts and SUSE 12 completely because of resource issues and timeouts in order to get a consistent toolchain deployment. We should lock in new builders for 6.0 with the v4 toolchain once we have these problems fixed.