Compiling with libmalloc: Make sure 'malloc' is in the dependency list for router, scheduler, and zmsh in the Dependencies file. Go into the libmalloc directory and run 'make' to create libmalloc_d.a. Then run 'make' in the toplevel directory. In SunOS 4.1[.1], there is a bug in the localtime.o file in the C library; it stomps on a byte beyond what has been allocated. If you have source, a patch is to change line 202 of localtime.c to: sp->chars = (char *)calloc((unsigned)sp->charcnt + 1, If you don't fix this somehow (e.g. in the source, by leaning on vendor, or by redefining calloc() to always return an extra byte), the debugging malloc will complain. The XFER define (in DEFS in the Config file) will enable the 'm' option in the router. It takes a filename argument, and writes a trace of malloc activity to the named file. The MALLOC_TRACE define enables code in the malloc library to stash the location of various function calls (which indirectly affect the heap). This information will appear on stderr (for router, the log file).