The fundamental problem with build systems is that they are built on top of command-line tool invocation, and command-line tool invocation is an extremely leaky

The fundamental problem with build systems is that they are built on top of command-line tool invocation, and command-line tool invocation is an extremely leaky abstraction; it breaks whenever the tools themselves are missing or broken. When you abstract away from this, you have to be very careful to maintain transparency all the way down, or else a wide variety of common problems become impossible to debug. Most of the current crop of tools fails miserably at this. Whenever something goes wrong in ant, or autoconf, or jam, it's always a nightmare to debug; and the more they try to be helpful, the worse it gets.