how does that fit into a build system? why would you require inspection of a running program to resolve build-time dependencies? and moreover, it's not like running a binary requires it to open all of the header and source files needed at build time, so how would you glean any useful data from it?

and what about systems that don't have strace, like BSD or OSX or solaris or windows? there's dtrace on those platforms (minus windows), which requires root, and requiring root access for dependency resolution isn't exactly a great idea.