IMHO SCons had some nice ideas but it falls down in practice in non-trivial projects. Wrestling with eels is easier than doing cross-platform builds in SCons. And while I do love Python, I think using a fully-fledged language is a mistake.
I think a declarative DSL with scripting hooks behind it is a better model. Having used many, many build systems over the years, I've never found one I thought truly got things right (though several came close).
I actually think the ideas behind bjam ought to be revisited. It had a declarative style, with scripting to support it. The implementation was awful sadly; the tiniest mistake or typo would send the parser into a tailspin and the documentation was truly confusing. Any errors were presented to the user at the scripting level, which was even more confusing. But the idea of having toolchains defined separately, and having traits and features was brilliant. There's a lot to learn from there.
I think a declarative DSL with scripting hooks behind it is a better model. Having used many, many build systems over the years, I've never found one I thought truly got things right (though several came close).
I actually think the ideas behind bjam ought to be revisited. It had a declarative style, with scripting to support it. The implementation was awful sadly; the tiniest mistake or typo would send the parser into a tailspin and the documentation was truly confusing. Any errors were presented to the user at the scripting level, which was even more confusing. But the idea of having toolchains defined separately, and having traits and features was brilliant. There's a lot to learn from there.