Merge pull request #4048 from rgrinberg/subst-debug-backtrace

Fix dune subst not to initialize root

bin/common.ml

@@ -118,6 +118,12 @@ let footer =
 
 let copts_sect = "COMMON OPTIONS"
 
+let debug_backtraces =
+  Arg.(
+    value & flag
+    & info [ "debug-backtraces" ] ~docs:copts_sect
+        ~doc:{|Always print exception backtraces.|})
+
 let examples = function
   | [] -> `Blocks []
   | _ :: _ as examples ->
@@ -475,11 +481,7 @@ let term =
     Arg.(
       value & flag
       & info [ "debug-findlib" ] ~docs ~doc:{|Debug the findlib sub-system.|})
-  and+ debug_backtraces =
-    Arg.(
-      value & flag
-      & info [ "debug-backtraces" ] ~docs
-          ~doc:{|Always print exception backtraces.|})
+  and+ debug_backtraces = debug_backtraces
   and+ debug_artifact_substitution =
     Arg.(
       value & flag

bin/common.mli

@@ -60,6 +60,8 @@ val footer : Cmdliner.Manpage.block
 
 val term : t Cmdliner.Term.t
 
+val debug_backtraces : bool Cmdliner.Term.t
+
 val config_term : Dune_engine.Config.t Cmdliner.Term.t
 
 val display_term : Dune_engine.Config.Display.t option Cmdliner.Term.t

bin/subst.ml

@@ -58,9 +58,16 @@ let man =
 let info = Term.info "subst" ~doc ~man
 
 let term =
-  let+ common = Common.term in
-  Common.set_common ~log_file:No_log_file common ~targets:[];
-  let config = Common.config common in
+  let+ () = Common.build_info
+  and+ debug_backtraces = Common.debug_backtraces in
+  let config : Config.t =
+    { Config.default with display = Quiet; concurrency = Fixed 1 }
+  in
+  Dune_engine.Clflags.debug_backtraces debug_backtraces;
+  Path.set_root (Path.External.cwd ());
+  Path.Build.set_build_dir (Path.Build.Kind.of_string Common.default_build_dir);
+  Config.init config;
+  Log.init_disabled ();
   Dune_engine.Scheduler.go ~config Watermarks.subst
 
 let command = (term, info)