+Parallel builds: On failure, wait for other jobs to finish.
+
+Conditional sections (same as "ifeq" etc in make).
+
+Let within functions and goals, eg:
+ function foo () =
+ let temp = "%bar%baz";
+ { .... }
+Unclear if this would be helpful or not.
+
+Implement more make functions, see:
+https://www.gnu.org/software/make/manual/html_node/Functions.html#Functions
+
+Split "flags" strings. eg. Currently there is no way to pass
+$CFLAGS from autoconf into a goalfile.
+
+Make re-execs itself if the Makefile (or any include) changes, and
+goals should do something similar. See:
+https://www.gnu.org/software/make/manual/html_node/Remaking-Makefiles.html
+
+Code should be an expression, eg this ought to work:
+let foo = { echo "hello" }
+and/or anonymous functions:
+let foo = function (arg) { ... }
+
+Infinite loop when you have this goal:
+goal pod2man (page, section) = "docs/%page.%section" : "docs/%page.pod" { ... }
+This is caused by %section matching "pod" so the rule is called
+again, even if the local file docs/%page.pod actually exists.