Overriding qbs properties behaves differently with and without the "modules." prefix

There seems to be no way to set default installation prefix for a qbs project.

I've tried adding

qbs.installPrefix: qbs.targetOS.contains("linux") ? "/usr/local" : ""

line to Project and Product.

Adding it to Project doesn't take any effect on it's Products and when it's set in Product the path "/usr/local" is used even when another path was passed through the command line.

Interestingly, in the latter case it's possible to override install prefix with "products.product.qbs.installPrefix:/path", but this is inconvenient.