Hi Robert,
Thanks for the bug-report! This input file is not covered by the tests, and it should. Could you submit an issue at [1]? It is also easy to fix, see below.
I opened issue #98 [1]. Should I just open issues for such problems from now on to keep the mailing list free of clutter? :)
The error you see is related to implementing the issues 36 and 93, [2,3], i.e. a unification of passing (extra) arguments to BC, material, and region definition functions. There is now a new keyword 'functions', where a function to be used should be registered, and any extra parameters are handled there too. The function is then used by its name only, see, for example, input/octahedron.py (or "git grep 'functions =" to see all the inputs using this feature).
Would you like to try and fix it yourself?
Ok, based off input/octahedron.py I think was able to figure out how to add the select_circ function. I posted the code in a reply to [1]. However, now I'm getting an IndexError exception which seems to be coming from the material definitions (see the reply to the issue). I'll take another look into that later on.
cheers, r.
Cheers! Logan