Fix crash when evaluating mdx stanza with missing local packages

Signed-off-by: Craig Ferguson <[email protected]>

CHANGES.md

@@ -49,6 +49,9 @@ next
 - Insert correct extension name when editing `dune-project` files. Previously,
   dune would just insert the stanza name. (#3649, fixes #3624, @rgrinberg)
 
+- Fix crash when evaluating an `mdx` stanza that depends on unavailable
+  packages. (#3650, @CraigFe)
+
 2.6.1 (02/07/2020)
 ------------------
 

src/dune/gen_rules.ml

@@ -129,7 +129,7 @@ end = struct
       Cinaps.gen_rules sctx cinaps ~dir ~scope;
       empty_none
     | Mdx.T mdx ->
-      Mdx.gen_rules ~sctx ~dir mdx;
+      Mdx.gen_rules ~sctx ~dir ~expander mdx;
       empty_none
     | _ -> empty_none
 

src/dune/mdx.ml

@@ -169,7 +169,7 @@ let files_to_mdx t ~sctx ~dir =
 
 (** Generates the rules for a single [src] file covered covered by the given
     [stanza]. *)
-let gen_rules_for_single_file stanza ~sctx ~dir ~mdx_prog src =
+let gen_rules_for_single_file stanza ~sctx ~dir ~expander ~mdx_prog src =
   let loc = stanza.loc in
   let files = Files.from_source_file src in
   (* Add the rule for generating the .mdx.deps file with ocaml-mdx deps *)
@@ -180,17 +180,15 @@ let gen_rules_for_single_file stanza ~sctx ~dir ~mdx_prog src =
     let deps = Build.map (Deps.read files) ~f:(Deps.to_dep_set ~dir) in
     let dyn_deps = Build.map deps ~f:(fun d -> ((), d)) in
     let pkg_deps =
-      let context = Super_context.context sctx in
-      let packages = Super_context.packages sctx in
       stanza.packages
       |> List.map ~f:(fun pkg ->
-             let pkg = Package.Name.Map.find_exn packages pkg in
-             Build.alias (Build_system.Alias.package_install ~context ~pkg))
+             Dep_conf.Package
+               (Package.Name.to_string pkg |> String_with_vars.make_text loc))
     in
     let prelude_args =
       List.concat_map stanza.preludes ~f:(Prelude.to_args ~dir)
     in
-    Build.(with_no_targets (all_unit pkg_deps))
+    Build.(with_no_targets (Dep_conf_eval.unnamed ~expander pkg_deps))
     >>> Build.with_no_targets (Build.dyn_deps dyn_deps)
     >>> Command.run ~dir:(Path.build dir) mdx_prog
           ( [ Command.Args.A "test" ] @ prelude_args
@@ -204,10 +202,11 @@ let gen_rules_for_single_file stanza ~sctx ~dir ~mdx_prog src =
     (Build.with_no_targets diff_action)
 
 (** Generates the rules for a given mdx stanza *)
-let gen_rules t ~sctx ~dir =
+let gen_rules t ~sctx ~dir ~expander =
   let files_to_mdx = files_to_mdx t ~sctx ~dir in
   let mdx_prog =
     Super_context.resolve_program sctx ~dir ~loc:(Some t.loc)
       ~hint:"opam install mdx" "ocaml-mdx"
   in
-  List.iter files_to_mdx ~f:(gen_rules_for_single_file t ~sctx ~dir ~mdx_prog)
+  List.iter files_to_mdx
+    ~f:(gen_rules_for_single_file t ~sctx ~dir ~expander ~mdx_prog)

src/dune/mdx.mli

@@ -7,4 +7,5 @@ type t
 type Stanza.t += T of t
 
 (** Genrates the rules to handle the given mdx stanza *)
-val gen_rules : t -> sctx:Super_context.t -> dir:Path.Build.t -> unit
+val gen_rules :
+  t -> sctx:Super_context.t -> dir:Path.Build.t -> expander:Expander.t -> unit

test/blackbox-tests/test-cases/mdx-stanza.t/run.t

@@ -49,140 +49,19 @@ the stanza
   $ dune runtest --root local-package
   Entering directory 'local-package'
 
-Even if the packages is unrelated:
+Dune should not fail if the `packages` are not available at evaluation time
+(regression test fixed by ocaml/dune#3650)
+
+  $ cd local-package-unrelated && dune build -p unrelated-package; cd ../
+
+Dune will fail if the `packages` entries are not avaliable at exeuction time
 
   $ cd local-package-unrelated && dune runtest -p unrelated-package; cd ../
-  Error: exception { exn = ("Map.find_exn: failed to find key", { key = 2; keys
-  = [ 1 ] })
-  ; backtrace =
-      [ { ocaml =
-            "Raised at file \"src/stdune/code_error.ml\", line 9, characters
-  30-62\n\
-             Called from file \"src/dune/mdx.ml\", line 187, characters
-  23-61\n\
-             Called from file \"list.ml\", line 103, characters 22-25\n\
-             Called from file \"src/stdune/list.ml\", line 5, characters
-  19-33\n\
-             Called from file \"src/dune/mdx.ml\", line 185, characters
-  6-196\n\
-             Called from file \"list.ml\", line 110, characters 12-15\n\
-             Called from file \"src/dune/gen_rules.ml\", line 128, characters
-  6-34\n\
-             Called from file \"src/dune/gen_rules.ml\", line 135, characters
-  6-96\n\
-             Called from file \"list.ml\", line 121, characters 24-34\n\
-             Called from file \"src/dune/gen_rules.ml\", line 138, characters
-  4-112\n\
-             Called from file \"src/dune/gen_rules.ml\", line 218, characters
-  4-119\n\
-             Called from file \"src/dune/gen_rules.ml\", line 349, characters
-  24-59\n\
-             Called from file \"src/stdune/exn.ml\", line 12, characters
-  8-11\n\
-             Re-raised at file \"src/stdune/exn.ml\", line 18, characters
-  4-11\n\
-             Called from file \"src/memo/implicit_output.ml\", line 120,
-  characters 4-162\n\
-             Called from file \"src/dune/rules.ml\" (inlined), line 192,
-  characters 20-71\n\
-             Called from file \"src/dune/rules.ml\", line 195, characters
-  20-33\n\
-             Called from file \"src/dune/build_system.ml\", line 900,
-  characters 6-76\n\
-             Called from file \"src/stdune/exn_with_backtrace.ml\", line 9,
-  characters 8-12\n\
-             "
-        ; memo = ("load-dir", In_build_dir "default")
-        }
-      ; { ocaml =
-            "Raised at file \"src/stdune/code_error.ml\", line 9, characters
-  30-62\n\
-             Called from file \"src/dune/mdx.ml\", line 187, characters
-  23-61\n\
-             Called from file \"list.ml\", line 103, characters 22-25\n\
-             Called from file \"src/stdune/list.ml\", line 5, characters
-  19-33\n\
-             Called from file \"src/dune/mdx.ml\", line 185, characters
-  6-196\n\
-             Called from file \"list.ml\", line 110, characters 12-15\n\
-             Called from file \"src/dune/gen_rules.ml\", line 128, characters
-  6-34\n\
-             Called from file \"src/dune/gen_rules.ml\", line 135, characters
-  6-96\n\
-             Called from file \"list.ml\", line 121, characters 24-34\n\
-             Called from file \"src/dune/gen_rules.ml\", line 138, characters
-  4-112\n\
-             Called from file \"src/dune/gen_rules.ml\", line 218, characters
-  4-119\n\
-             Called from file \"src/dune/gen_rules.ml\", line 349, characters
-  24-59\n\
-             Called from file \"src/stdune/exn.ml\", line 12, characters
-  8-11\n\
-             Re-raised at file \"src/stdune/exn.ml\", line 18, characters
-  4-11\n\
-             Called from file \"src/memo/implicit_output.ml\", line 120,
-  characters 4-162\n\
-             Called from file \"src/dune/rules.ml\" (inlined), line 192,
-  characters 20-71\n\
-             Called from file \"src/dune/rules.ml\", line 195, characters
-  20-33\n\
-             Called from file \"src/dune/build_system.ml\", line 900,
-  characters 6-76\n\
-             Called from file \"src/stdune/exn_with_backtrace.ml\", line 9,
-  characters 8-12\n\
-             Re-raised at file \"src/stdune/exn.ml\", line 36, characters
-  27-56\n\
-             Called from file \"src/dune/build_system.ml\", line 1046,
-  characters 12-43\n\
-             Called from file \"src/stdune/exn_with_backtrace.ml\", line 9,
-  characters 8-12\n\
-             "
-        ; memo = ("load-dir", In_build_dir ".aliases/default")
-        }
-      ]
-  ; outer_call_stack = []
-  }
-  Raised at file "src/stdune/code_error.ml", line 9, characters 30-62
-  Called from file "src/dune/mdx.ml", line 187, characters 23-61
-  Called from file "list.ml", line 103, characters 22-25
-  Called from file "src/stdune/list.ml", line 5, characters 19-33
-  Called from file "src/dune/mdx.ml", line 185, characters 6-196
-  Called from file "list.ml", line 110, characters 12-15
-  Called from file "src/dune/gen_rules.ml", line 128, characters 6-34
-  Called from file "src/dune/gen_rules.ml", line 135, characters 6-96
-  Called from file "list.ml", line 121, characters 24-34
-  Called from file "src/dune/gen_rules.ml", line 138, characters 4-112
-  Called from file "src/dune/gen_rules.ml", line 218, characters 4-119
-  Called from file "src/dune/gen_rules.ml", line 349, characters 24-59
-  Called from file "src/stdune/exn.ml", line 12, characters 8-11
-  Re-raised at file "src/stdune/exn.ml", line 18, characters 4-11
-  Called from file "src/memo/implicit_output.ml", line 120, characters 4-162
-  Called from file "src/dune/rules.ml" (inlined), line 192, characters 20-71
-  Called from file "src/dune/rules.ml", line 195, characters 20-33
-  Called from file "src/dune/build_system.ml", line 900, characters 6-76
-  Called from file "src/stdune/exn_with_backtrace.ml", line 9, characters 8-12
-  Re-raised at file "src/stdune/exn.ml", line 36, characters 27-56
-  Called from file "src/dune/build_system.ml", line 1046, characters 12-43
-  Called from file "src/stdune/exn_with_backtrace.ml", line 9, characters 8-12
-  Re-raised at file "src/stdune/exn.ml", line 36, characters 27-56
-  Called from file "src/dune/build_system.ml", line 685, characters 10-23
-  Called from file "src/dune/build_system.ml", line 682, characters 17-34
-  Called from file "src/dune/build.ml", line 293, characters 9-22
-  Called from file "src/dune/build.ml", line 284, characters 58-73
-  Called from file "src/dune/build.ml", line 284, characters 42-57
-  Called from file "src/dune/build.ml", line 284, characters 42-57
-  Called from file "src/dune/build.ml", line 284, characters 58-73
-  Called from file "src/dune/build_system.ml", line 1237, characters 24-39
-  Called from file "src/dune/build_system.ml", line 1850, characters 8-97
-  Called from file "src/fiber/fiber.ml", line 109, characters 10-15
-  Re-raised at file "src/stdune/exn.ml", line 36, characters 27-56
-  Called from file "src/fiber/fiber.ml", line 80, characters 10-17
-
-  I must not crash.  Uncertainty is the mind-killer. Exceptions are the
-  little-death that brings total obliteration.  I will fully express my cases. 
-  Execution will pass over me and through me.  And when it has gone past, I
-  will unwind the stack along its path.  Where the cases are handled there will
-  be nothing.  Only I will remain.
+  File "dune", line 1, characters 0-40:
+  1 | (mdx
+  2 |  (files README.md)
+  3 |  (packages pkg))
+  Error: Package pkg does not exist
 
 You can set MDX preludes using the preludes field of the stanza