Now that valgrind works I run it on linux X86_64 against fossil-scm compiled with tcc and got this:
==32200== Nulgrind, the minimal Valgrind tool
==32200== Copyright (C) 2002-2013, and GNU GPL'd, by Nicholas Nethercote.
==32200== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info
==32200== Command: /home/mingo/dev/c/fossil-src-20140127173344/fossil server
==32200==
==32200==
==32200== Process terminating with default action of signal 11 (SIGSEGV)
==32200== Access not within mapped region at address 0x18
==32200== at 0x46BEB49: _int_malloc (malloc.c:3827)
==32200== by 0x46C0F94: malloc (malloc.c:2924)
==32200== by 0x8220083: __va_start (in /home/mingo/dev/c/fossil-src-20140127173344/fossil)