Get rid of the wasm-spec submodule

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "vendor/wasm-spec"]
-	path = vendor/wasm-spec
-	url = https://github.com/WebAssembly/multi-value/

README.md

@@ -48,34 +48,42 @@ To build `asc.js`, the JavaScript library, use
 nix-build -A js
 ```
 
-If you want to install `wasm` and `dvm` binaries with nix (for example because
-you maintain your Ocaml installation manually), run
-
-```
-nix-env -i -f . -A wasm
-nix-env -i -f . -A dvm
-```
-To update the `dev` checkout and install `dvm` in one go, run `./update-dvm.sh`.
 
 By default, `dvm` is built using the V8 engine. To build with the Haskell
 engine, pass `--arg v8 false` to any of the above `nix-*` commands.
 
-## Installation and development without Nix
+## Development without Nix
 
-You do not have to use nix:
+You can get a development environment that is independent of nix (although
+installing all required tools without nix is out of scope).
 
  * Use your system’s package manager to install `ocaml` and
    [`opam`](https://opam.ocaml.org/doc/Install.html)
  * Install the packages listed as `OPAM_PACKAGES` in `src/Makefile`:
    ```
    opam install num vlq yojson bisect_ppx bisect_ppx-ocamlbuild menhir
    ```
- * Install the `wasm` package in `vendor/wasm-spec/interpreter/` by running
-   `make install` therein.
- * Make sure `wasm` (a binary found in `vendor/wasm-spec/interpreter`) is in
-   the path to run the `run` tests.
- * Make sure `dvm` (a binary from the `hs-dfinity-dvm` package) is in the path
-   to run the `run-dfinity` tests.
+ * Install the `wasm` package. We use a newer version than is on opam, and a
+   fork that supports the multi-value extension. See `nix/ocaml-wasm.nix` for
+   the precise repository and version. You can use `nix` to fetch the correct
+   source for you, and run the manual installation inside:
+   ```
+   cd $(nix-build -Q -A wasm.src)
+   make install
+   ```
+ * Install the `wasm` tool, using
+   ```
+   nix-env -i -f . -A wasm
+   ```
+ * Install the `dvm` tool, using
+   ```
+   nix-env -i -f . -A dvm
+   ```
+   or simply
+   ```
+   ./update-dvm.sh
+   ```
+   which also updates the `dev` checkout.
 
 ## Create a coverage report
 

nix/ocaml-wasm.nix

@@ -6,16 +6,10 @@ if !stdenv.lib.versionAtLeast ocaml.version "4.02"
 then throw "wasm is not available for OCaml ${ocaml.version}"
 else
 
-# Lets use fetch from git, this way nix has to cache less
-# if !builtins.pathExists ../vendor/wasm-spec/interpreter
-# then throw "submodule in vendor/wasm-spec missing. Run git submodule update --init"
-# else
-
 stdenv.mkDerivation rec {
   name = "ocaml${ocaml.version}-wasm-${version}";
   version = "1.0";
 
-  #src = ../vendor/wasm-spec;
   src = fetchFromGitHub {
     owner = "WebAssembly";
     repo = "multi-value";