Enabling Traps on Mac G5

Hello,

I'm using CMUCL 19c on a PowerMac G5, and I keep having the same problem when trying to enable traps.

After starting CMUCL, I type 

(set-floating-point-modes :traps '(:underflow :overflow :inexact :invalid))

I then type 

(get-floating-point-modes)

and I see 

(:TRAPS NIL :ROUNDING-MODE :NEAREST :CURRENT-EXCEPTIONS (:INEXACT)
 :ACCRUED-EXCEPTIONS (:INEXACT) :FAST-MODE NIL)

This is consistent.  The reported list of traps is always nil.  I tried setting the traps in a .cmucl-init file, but that didn't work either.  The code works as expected in the Linux version, so I'm starting to think that floating point traps don't work on the G5 architecture (or powerpc in general).  Is this the case?

Will