Need example of plain C

[talex5]

I'm trying to make an assemblage project with a C file (timestamp_stubs.c, containing some in-line assembler). It's not obvious to me how to make it build this. I tried:

open Assemblage

let timestamp_stubs = c "timestamp_stubs" (`Path [])

let profile_ml = unit "profile" (`Path []) ~deps:[
  pkg_pp "sexplib.syntax";
  pkg "sexplib";
  pkg "lwt";
  timestamp_stubs;
]

let profile = lib "mirage_profile" (`Units [profile_ml; timestamp_stubs])
let () = assemble (project ~version:"0.1" "mirage_profile" [profile])

Running make builds profile.ml but seems to ignore timestamp_stubs. It also appears blank in the describe output:

$ assemblage describe
==> Loading assemble.ml 

==> mirage_profile 0.1
└─┬─ lib-mirage_profile
  ├─ profile.ml       profile.mli      
  └─

[talex5]

(closing as project is obsolete)