* Deal with directory components in header file references (e.g.,

`#include "foo/../bar/bla.h"') by building an appropriate tree of
  symlinks.

examples/default.nix

@@ -1,3 +1,4 @@
 [ (import ./trivial)
   (import ./simple-header)
+  (import ./not-so-simple-header)
 ]

examples/not-so-simple-header/bar/hello.h

@@ -0,0 +1 @@
+#define WHAT "World"

examples/not-so-simple-header/default.nix

@@ -0,0 +1,14 @@
+let {
+
+  inherit (import ../../lib) compileC link;
+
+  hello = link {objects = compileC {
+    main = ./foo/hello.c;
+    localIncludes = [
+      [./foo/fnord/indirect.h "fnord/indirect.h"]
+      [./bar/hello.h "fnord/../../bar/hello.h"]
+    ];
+  };};
+
+  body = [hello];
+}

examples/not-so-simple-header/foo/fnord/indirect.h

@@ -0,0 +1,3 @@
+#define HELLO "Hello"
+
+#include "../../bar/hello.h"

examples/not-so-simple-header/foo/hello.c

@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+#include "fnord/indirect.h"
+
+int main(int argc, char * * argv)
+{
+    printf(HELLO " " WHAT "\n");
+    return 0;
+}