I don't know if this is deliberate or not.
/opt/SUNWspro/bin/cc -DHAVE_CONFIG_H -I. -I. -I../.. -I../.. -I../../dotneato/dotgen -I../../dotneato/neatogen -I../../dotneato/twopigen -I../../dotneato/gvrender -I../../graph -I../../cdt -I../../pathplan -I../../gd -I/home/jjones/include -g -c diagen.c -KPIC -DPIC -o diagen.o
"diagen.c", line 798: syntax error before or at: /
"diagen.c", line 809: cannot recover from previous errors
cc: acomp failed for diagen.c
gmake[3]: *** [diagen.lo] Error 1
gmake[3]: Leaving directory `/bb/home3/jjones/src/graphviz-1.12/dotneato/common'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/bb/home3/jjones/src/graphviz-1.12/dotneato'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/bb/home3/jjones/src/graphviz-1.12'
gmake: *** [all] Error 2