Python Safe Globals now have more reliable triggering of OnChange call. Added "Onchange" object to accessible runtime variables that let user python code see count of changes and first and last values.
<xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C %(buildpath)s all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>