Okay, after some more troubleshooting, I found out something that may be important.
When I run make functor.cmi, the Applicative module builds, but when I run make stdlib__functor.cmi, it does not. Alternatively, if I refer to Stdlib__functor instead of Functor in applicative.mli and applicative.ml, the Applicative module builds. I see other standard library modules refer to each other without the Stdlib__ prefix, so what’s wrong with my build?
I would like to note that I have added the appropriate names to stdlib/Makefile stdlib/StdlibModules.
Update: I fixed the problem: I didn’t add my new modules to the Stdlib module. IIRC this is a new change to the standard library organization for release 4.07.
However, there is a new problem: stdlib__sys.cmi doesn’t seem to be built when I run make all, leading to compile errors.
Update: the stdlib__sys.cm_ listings don’t appear in .depend… could this be because sys.ml is generated? Also, when I run make depend in the stdlib directory, ../tools/ocamldep doesn’t exist…
Update: I recloned the repository. Now, when I run make world.opt, the error is Required module Stdlib__functor is unavailable in file _none_, the toplevel?