Disappearing fixed effects

[samellisq]

Very obscure issue. When running a bison_model() with fixed effects. If any of your fixed effects end in 1 they disappear during the process of assembling the model. i.e. when making the beta design matrix they do not appear, and are then not applied in the stan model. Oddly it happens with ending in 1 but not in 0.

I'm pretty sure it happens in the get_model_spec function somewhere but haven't been able to trace any further.

It is easy to fix by renaming of course so this could be a non-issue, but jsut thought I'd raise it.