Add a reproduction case for issue ocaml#4682

craigfe · rgrinberg · commit b9da25284fe7 · 2021-06-18T01:07:44.000-07:00
Signed-off-by: Craig Ferguson &lt;me@craigfe.io&gt;
diff --git a/test/blackbox-tests/test-cases/github4682.t/dune b/test/blackbox-tests/test-cases/github4682.t/dune
@@ -0,0 +1,5 @@
+(executable
+ (name main)
+ (root_module root)
+ (libraries unix)
+ (preprocess (pps ppx)))
diff --git a/test/blackbox-tests/test-cases/github4682.t/main.ml b/test/blackbox-tests/test-cases/github4682.t/main.ml
@@ -0,0 +1 @@
+module X = Root.Unix
diff --git a/test/blackbox-tests/test-cases/github4682.t/ppx/dune b/test/blackbox-tests/test-cases/github4682.t/ppx/dune
@@ -0,0 +1,5 @@
+(library
+ (name ppx)
+ (kind ppx_rewriter)
+ (libraries lib)
+ (ppx.driver (main Ppx.main)))
diff --git a/test/blackbox-tests/test-cases/github4682.t/ppx/ppx.ml b/test/blackbox-tests/test-cases/github4682.t/ppx/ppx.ml
@@ -0,0 +1 @@
+let main () = ()
diff --git a/test/blackbox-tests/test-cases/github4682.t/ppx/ppx.mli b/test/blackbox-tests/test-cases/github4682.t/ppx/ppx.mli
@@ -0,0 +1 @@
+val main : unit -> unit
diff --git a/test/blackbox-tests/test-cases/github4682.t/run.t b/test/blackbox-tests/test-cases/github4682.t/run.t
@@ -0,0 +1,8 @@
+Attempting to use `(root_module ...)` with an executable that uses PPX results
+in an unexpected build failure:
+
+  $ dune build
+  Error: Multiple rules generated for _build/default/root.pp.ml-gen:
+  - dune:5
+  - <none>:1
+  [1]
