Turns out that in forcing git-lfs onto the path, I'd managed to break devtoolset-6. Now resolved that, and a build is running on tiger-sumire. It should start with w_2018_28 and pick up newer versions from there; I don't intend to backfill unless somebody expresses a requirement.
I'll do the same thing on Perseus in a moment.
Since I'm no longer in Princeton and hence not really paying attention to such things, I'm confused about where this code is actually needed. Are tiger-sumire and the Perseus head node still the most appropriate places? Should we be doing something different for Tiger Mk 2?