Avoid a symlink for dune

.gitignore

@@ -4,7 +4,6 @@ charon/tests/cargo/**/target
 
 # Temporary files we don't want to commit
 charon-ml/tests/serialized
-charon-ml/tests/test-outputs/*
 /bin
 
 # Generated by charon

charon-ml/tests/Tests.ml

@@ -11,10 +11,13 @@ let () =
     log#set_level EL.Debug
   with Not_found -> log#set_level EL.Info
 
+let llbc_dir =
+  try Unix.getenv "CHARON_TESTS_DIR" with Not_found -> "../../charon/tests/ui"
+
 (* Call the tests *)
 (* llbc files are copied into the `_build` dir by the `(deps)` rule in `./dune`. *)
-let () = Test_Deserialize.run_tests "test-outputs"
-let () = Test_NameMatcher.run_tests "test-outputs/ml-name-matcher-tests.llbc"
+let () = Test_Deserialize.run_tests llbc_dir
+let () = Test_NameMatcher.run_tests (llbc_dir ^ "/ml-name-matcher-tests.llbc")
 
 let () =
-  Test_NameMatcher.run_tests "test-outputs/ml-mono-name-matcher-tests.llbc"
+  Test_NameMatcher.run_tests (llbc_dir ^ "/ml-mono-name-matcher-tests.llbc")

charon-ml/tests/dune

@@ -3,5 +3,5 @@
  (modes byte exe)
  (modules Tests Test_Deserialize Test_NameMatcher)
  (deps
-  (glob_files_rec ./test-outputs/*))
+  (glob_files_rec ../../charon/tests/ui/*))
  (libraries charon))

dune

@@ -0,0 +1 @@
+(data_only_dirs charon)

nix/charon-ml.nix

@@ -71,12 +71,6 @@ let
       duneVersion = "3";
       inherit src;
 
-      OCAMLPARAM = "_,warn-error=+A"; # Turn all warnings into errors.
-      preCheck =
-        if doCheck then ''
-          ln -sf ${charon}/tests-llbc charon-ml/tests/test-outputs
-        '' else
-          "";
       propagatedBuildInputs = with ocamlPackages; [
         core
         ppx_deriving
@@ -89,7 +83,17 @@ let
         unionFind
         ocaml-ng.ocamlPackages_4_14.ppx_tools # to view the output of visitor derivation
       ];
+
+      OCAMLPARAM = "_,warn-error=+A"; # Turn all warnings into errors.
+      CHARON_TESTS_DIR = lib.optionalString doCheck "${charon}/tests-llbc"; # Tell the tests where to find the llbc files.
+
       inherit doCheck;
+      preBuild = ''
+        # This refers to a directory that doesn't exist in the current
+        # environment. We don't need dune here because tests can access the
+        # files directly, so we remove the dependency clause.
+        sed -i 's#(glob_files_rec [^)]*)##' charon-ml/tests/dune
+      '';
 
       passthru = { inherit charon-ml-tests charon-ml-check-fmt; };
     };