Autoinitialization of parts causes parts build order to change if variables are interpolated in other sections

[whit morriss]

zc.buildout-1.0.2-py2.5.egg L942 buildout.py

I have part named "nginx-conf" that refers to a variable defined in part "app": upstream=localhost:${app:port}. Since nginx is built near the beginning, and parts are added to buildout._part as they are initialized (buildout.py L791, L876) when accessed.

Buildout._parts is then used to determine the order that parts are built (L296). I expect the build to run in the order specified in buildout:parts, instead "app" builds immediately after nginx-conf.

I can work around this by putting variables needed in multiple areas in the buildout namespace but it feels like either that should be enforced to prevent unexpected sideeffects(no interpolation of variable across parts), or the actual variable buildout:parts should directly determine run order.