I’d like to report that the issue appears to be resolved, thanks to work from rdb and David! 
(This is as of the (pretty recent) version that I’ve been building, of course.)
There is one caveat for anyone who wants to build their own version of the runtime distributable: On my machine, at least, (and noting that I’m building on Ubuntu 14.04) it seems that having the SDK installed when building the distributable may result in a distributable that doesn’t work correctly. Simply uninstalling the SDK for the duration of the build seems to correct the problem, and installing the SDK after the build has completed seems to incur no further problems.