Do not show command lines when running inside dune

CHANGES.md

@@ -1,3 +1,10 @@
+2.2.0 (unreleased)
+------------------
+
+- By default, do not show the full command line of commands executed
+  by `dune` when `dune` is executed inside `dune`. This is to make
+  integration tests more reproducible (#3042, @diml)
+
 2.1.3 (16/01/2020)
 ------------------
 

src/dune/config.ml

@@ -32,7 +32,11 @@ let inside_dune = Option.is_some (Env.get Env.initial "INSIDE_DUNE")
 let inside_ci = Option.is_some (Env.get Env.initial "CI")
 
 let show_full_command_on_error () =
-  inside_dune || inside_ci || !Clflags.always_show_command_line
+  !Clflags.always_show_command_line
+  || (* We want to show command lines in the CI, but not when running inside
+        dune. Otherwise tests would yield different result whether they are
+        executed locally or in the CI. *)
+  (inside_ci && not inside_dune)
 
 open Dune_lang.Decoder
 

test/blackbox-tests/test-cases/lint/run.t

@@ -4,7 +4,6 @@ The lint alias will run preprocessing actions listed under (lint):
   > let () = Printf.printf "%d\n" @@ 1 + 2
   > EOF
   $ dune build @detect/lint
-           ppx alias detect/lint
   File "detect/add.ml", line 1, characters 33-38:
   This addition can be done statically.
 

test/blackbox-tests/test-cases/private-modules/run.t

@@ -3,13 +3,13 @@
         runfoo alias default
   private module bar
 
-  $ dune build --root inaccessible-in-deps 2>&1 | grep -v "cd _build"
+  $ dune build --root inaccessible-in-deps 2>&1
   Entering directory 'inaccessible-in-deps'
-        ocamlc .foo.eobjs/byte/foo.{cmi,cmo,cmt} (exit 2)
   File "foo.ml", line 1, characters 0-5:
   1 | X.run ();;
       ^^^^^
   Error: Unbound module X
+  [1]
 
 Private modules are not excluded from the install file, but installed in the .private subdir
   $ dune build --root private-subdir | grep -i priv