This is possibly more of a WebOb thing than a Pyramid thing. WebOb
attempts to decode POST and GET variables when you ask for them, usually
If you want to continue to treat these requests as errors but suppress
exceptions, it's pretty easy, just register an exception view for
return 'Sorry, something is not encoded properly'
If, on the other hand, you don't want the request to be treated as an
error, but you want it to be accepted and processed by something, it's
probably possible, but how you do it would depend on the particulars of
the application. Note that anything that accesses request.POST or
request.params will trigger an attempt at decoding; some Pyramid
predicates do this themselves, and of course if your application does
this, it will trigger the same. So seeing a traceback in the context of
your particular application would probably be necessary.