a small verilog file from the altera simulation libraries...
Rolfs-Mac-Pro:~ rfie$ iverilog -o x -I. dffeas.v
dffeas.v:75: assert: elab_expr.cc:3709: failed assertion expr_type_ != IVL_VT_NO_TYPE
sh: line 1: 2461 Done /opt/local/lib/ivl/ivlpp -L -F"/var/folders/fq/9w37g8wx04745hf7bjsy7r2w0000gn/T//ivrlg22769f1d" -f"/var/folders/fq/9w37g8wx04745hf7bjsy7r2w0000gn/T//ivrlg2769f1d" -p"/var/folders/fq/9w37g8wx04745hf7bjsy7r2w0000gn/T//ivrli2769f1d"
2462 Abort trap: 6 | /opt/local/lib/ivl/ivl -C"/var/folders/fq/9w37g8wx04745hf7bjsy7r2w0000gn/T//ivrlh2769f1d" -C"/opt/local/lib/ivl/vvp.conf" -- -
If I remove the '!' in from of prn_in in line 75 (make !prn_in read prn_in) the compiler no longer crashes
I am using version 0.9.6, the crash happens on MacOS 64 bit and Linux 32 bit (and also in 0.9.5)
At line 75 an UDP is used (definition of the UDP in the include file)