diff --git a/otherlibs/cram/bin/dune b/otherlibs/cram/bin/dune
index 5cb0b5db460..77357820cc2 100644
--- a/otherlibs/cram/bin/dune
+++ b/otherlibs/cram/bin/dune
@@ -1,7 +1,7 @@
 (executable
  (name dune_cram)
  (libraries dune-private-libs.stdune dune-build-info cmdliner
-   build_path_prefix_map dune-private-libs.dune_re dune-configurator)
+   build_path_prefix_map dune-private-libs.dune_re)
  (preprocess (future_syntax)))
 
 (ocamllex cram_lexer)
diff --git a/otherlibs/cram/bin/sanitize.ml b/otherlibs/cram/bin/sanitize.ml
index 386d76fc450..789acb504dd 100644
--- a/otherlibs/cram/bin/sanitize.ml
+++ b/otherlibs/cram/bin/sanitize.ml
@@ -2,7 +2,6 @@ open Stdune
 open Cmdliner
 open Import.Let_syntax
 module Re = Dune_re
-module Configurator = Configurator.V1
 
 let rewrite_paths build_path_prefix_map =
   match Build_path_prefix_map.decode_map build_path_prefix_map with
@@ -18,44 +17,9 @@ let rewrite_paths build_path_prefix_map =
       Re.replace abs_path_re s ~f:(fun g ->
           Build_path_prefix_map.rewrite map (Re.Group.get g 0))
 
-let make_ext_replace config =
-  let tbl =
-    List.filter_map [ "ext_exe"; "ext_dll"; "ext_asm"; "ext_lib"; "ext_obj" ]
-      ~f:(fun var ->
-        match Configurator.ocaml_config_var config var with
-        | Some "" -> None
-        | Some s -> Some (s, "$" ^ var)
-        | None -> (
-          match (var, Configurator.ocaml_config_var config "system") with
-          | "ext_exe", Some "Win32" -> Some (".exe", var)
-          | _ -> None ))
-  in
-  let re =
-    Re.(
-      compile
-        (seq
-           [ diff any (char '/')
-           ; alt (List.map tbl ~f:(fun (s, _) -> str s))
-           ; eow
-           ]))
-  in
-  let map = String.Map.of_list_reduce tbl ~f:(fun _ x -> x) in
-  fun s ->
-    Re.replace re s ~f:(fun g ->
-        let s = Re.Group.get g 0 in
-        sprintf "%c%s" s.[0] (String.Map.find_exn map (String.drop s 1)))
-
-let sanitizer =
-  let ext_replace =
-    if Option.is_some (Env.get Env.initial "INSIDE_DUNE") then
-      make_ext_replace (Configurator.create "sanitizer")
-    else
-      fun s ->
-    s
-  in
-  fun (command : Sanitizer.Command.t) ->
-    command.output |> Ansi_color.strip |> ext_replace
-    |> rewrite_paths command.build_path_prefix_map
+let sanitizer (command : Sanitizer.Command.t) =
+  command.output |> Ansi_color.strip
+  |> rewrite_paths command.build_path_prefix_map
 
 let term =
   let+ () = Term.pure () in
diff --git a/test/blackbox-tests/test-cases/block-strings.t/run.t b/test/blackbox-tests/test-cases/block-strings.t/run.t
index 31be3a1e16d..ca8d9e6fd89 100644
--- a/test/blackbox-tests/test-cases/block-strings.t/run.t
+++ b/test/blackbox-tests/test-cases/block-strings.t/run.t
@@ -10,9 +10,9 @@
     ARFLAGS="$ARFLAGS" \
     CXX="$CXX" \
     CXXFLAGS="$CXXFLAGS" \
-    obj/libre2$ext_lib obj/so/libre2$ext_dll
-  cp libre2/obj/libre2$ext_lib libre2_c_stubs$ext_lib
-  cp libre2/obj/so/libre2$ext_dll dllre2_c_stubs$ext_dll
+    obj/libre2.a obj/so/libre2.so
+  cp libre2/obj/libre2.a libre2_c_stubs.a
+  cp libre2/obj/so/libre2.so dllre2_c_stubs.so
   ${.MAKE} -s -C libre2 clean
 
   $ dune build @new
@@ -27,9 +27,9 @@
     ARFLAGS="$ARFLAGS" \
     CXX="$CXX" \
     CXXFLAGS="$CXXFLAGS" \
-    obj/libre2$ext_lib obj/so/libre2$ext_dll
-  cp libre2/obj/libre2$ext_lib libre2_c_stubs$ext_lib
-  cp libre2/obj/so/libre2$ext_dll dllre2_c_stubs$ext_dll
+    obj/libre2.a obj/so/libre2.so
+  cp libre2/obj/libre2.a libre2_c_stubs.a
+  cp libre2/obj/so/libre2.so dllre2_c_stubs.so
   ${.MAKE} -s -C libre2 clean
 
   $ dune build @quoting-test
diff --git a/test/blackbox-tests/test-cases/cross-compilation.t/run.t b/test/blackbox-tests/test-cases/cross-compilation.t/run.t
index bb1d9f67cf0..5cf7d22f8dd 100644
--- a/test/blackbox-tests/test-cases/cross-compilation.t/run.t
+++ b/test/blackbox-tests/test-cases/cross-compilation.t/run.t
@@ -23,7 +23,7 @@
   42
   $ ls *.install
   p-foo.install
-  $ dune_cmd cat p-foo.install
+  $ dune_cmd cat p-foo.install | dune_cmd sanitize
   lib: [
     "_build/install/default.foo/lib/p/META" {"../../foo-sysroot/lib/p/META"}
     "_build/install/default.foo/lib/p/dune-package" {"../../foo-sysroot/lib/p/dune-package"}
diff --git a/test/blackbox-tests/test-cases/deprecated-library-name.t/run.t b/test/blackbox-tests/test-cases/deprecated-library-name.t/run.t
index dbe64028124..c715c5d3928 100644
--- a/test/blackbox-tests/test-cases/deprecated-library-name.t/run.t
+++ b/test/blackbox-tests/test-cases/deprecated-library-name.t/run.t
@@ -64,7 +64,7 @@ deprecated library will be resolved in the installed world only.
 
   $ (cd b
   > dune build @install --root .
-  > dune install --prefix $PWD/../_install)
+  > dune install --prefix $PWD/../_install 2>&1 | dune_cmd sanitize)
   Installing $TESTCASE_ROOT/b/../_install/lib/b/META
   Installing $TESTCASE_ROOT/b/../_install/lib/b/b$ext_lib
   Installing $TESTCASE_ROOT/b/../_install/lib/b/b.cma
diff --git a/test/blackbox-tests/test-cases/dune-package.t/run.t b/test/blackbox-tests/test-cases/dune-package.t/run.t
index ecd605f4f00..2fde15732dc 100644
--- a/test/blackbox-tests/test-cases/dune-package.t/run.t
+++ b/test/blackbox-tests/test-cases/dune-package.t/run.t
@@ -1,5 +1,5 @@
   $ dune build
-  $ dune_cmd cat _build/install/default/lib/a/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune_cmd cat _build/install/default/lib/a/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
   (lang dune <version>)
   (name a)
   (library
diff --git a/test/blackbox-tests/test-cases/duplicate-c-cxx-obj.t/run.t b/test/blackbox-tests/test-cases/duplicate-c-cxx-obj.t/run.t
index 5329b183ec7..65598f18ae2 100644
--- a/test/blackbox-tests/test-cases/duplicate-c-cxx-obj.t/run.t
+++ b/test/blackbox-tests/test-cases/duplicate-c-cxx-obj.t/run.t
@@ -7,7 +7,7 @@ stubs names, things are still broken if their .o files overlap:
   >  (c_names foo sub/foo))
   > EOF
 
-  $ dune build --root diff-stanza @all
+  $ dune build --root diff-stanza @all 2>&1 | dune_cmd sanitize
   Entering directory 'diff-stanza'
   File "dune", line 4, characters 10-13:
   4 |  (c_names foo))
@@ -16,7 +16,6 @@ stubs names, things are still broken if their .o files overlap:
   definition at dune:9.
   Hint: You can avoid the name clash by renaming one of the objects, or by
   placing it into a different directory.
-  [1]
 
 Another form of this bug is if the same source is present in different
 directories. In this case, the rules are fine, but this is probably not what the
diff --git a/test/blackbox-tests/test-cases/duplicate-c-cxx.t/run.t b/test/blackbox-tests/test-cases/duplicate-c-cxx.t/run.t
index 2f514863cd7..816753587d1 100644
--- a/test/blackbox-tests/test-cases/duplicate-c-cxx.t/run.t
+++ b/test/blackbox-tests/test-cases/duplicate-c-cxx.t/run.t
@@ -14,7 +14,7 @@ c_names and cxx_names with overlapping names in the same stanza
   [1]
 
 c_names with overlapping names in different stanzas
-  $ dune build --root diff-stanza @all
+  $ dune build --root diff-stanza @all 2>&1 | dune_cmd sanitize
   Entering directory 'diff-stanza'
   File "dune", line 4, characters 10-13:
   4 |  (c_names foo))
@@ -23,4 +23,3 @@ c_names with overlapping names in different stanzas
   definition at dune:9.
   Hint: You can avoid the name clash by renaming one of the objects, or by
   placing it into a different directory.
-  [1]
diff --git a/test/blackbox-tests/test-cases/foreign-library.t/run.t b/test/blackbox-tests/test-cases/foreign-library.t/run.t
index c25585105b3..d366d09f419 100644
--- a/test/blackbox-tests/test-cases/foreign-library.t/run.t
+++ b/test/blackbox-tests/test-cases/foreign-library.t/run.t
@@ -705,7 +705,7 @@ Testsuite for the (foreign_library ...) stanza.
 
   $ rm -rf _build
   $ touch external/external_library.opam
-  $ ( cd external && ../sdune build @install && ../sdune install --prefix install)
+  $ ( cd external && ../sdune build @install && ../sdune install --prefix install 2>&1 | dune_cmd sanitize )
   Installing install/lib/external_library/META
   Installing install/lib/external_library/correction.h
   Installing install/lib/external_library/dune-package
diff --git a/test/blackbox-tests/test-cases/foreign-stubs.t/run.t b/test/blackbox-tests/test-cases/foreign-stubs.t/run.t
index 0963880a713..b7a2a01a69e 100644
--- a/test/blackbox-tests/test-cases/foreign-stubs.t/run.t
+++ b/test/blackbox-tests/test-cases/foreign-stubs.t/run.t
@@ -116,10 +116,9 @@ Testsuite for the (foreign_stubs ...) field.
   > value foo(value unit) { return Val_int(9); }
   > EOF
 
-  $ ./sdune build
+  $ ./sdune build 2>&1 | dune_cmd sanitize
   File "dune", line 1, characters 0-0:
   Error: No rule found for libbar$ext_lib
-  [1]
 
 ----------------------------------------------------------------------------------
 * Build succeeds when a self-built archive exists.
@@ -476,7 +475,7 @@ setting [disable_dynamically_linked_foreign_archives] is [true] in the workspace
 * Make sure no rules are generated for foreign dynamically linked archives
 
   $ ./sdune build _build/default/dlltime.so
-  Error: Don't know how to build _build/default/dlltime$ext_dll
+  Error: Don't know how to build _build/default/dlltime.so
   [1]
 
 ----------------------------------------------------------------------------------
@@ -527,7 +526,7 @@ setting [disable_dynamically_linked_foreign_archives] is [true] in the workspace
   3 |  (name clock)
   4 |  (modules clock)
   5 |  (self_build_stubs_archive (time)))
-  Error: No rule found for dlltime_stubs$ext_dll
+  Error: No rule found for dlltime_stubs.so
   [1]
 
 ----------------------------------------------------------------------------------
diff --git a/test/blackbox-tests/test-cases/gen-opam-install-file.t/run.t b/test/blackbox-tests/test-cases/gen-opam-install-file.t/run.t
index 42b7e9e0d82..b97b93fd1fa 100644
--- a/test/blackbox-tests/test-cases/gen-opam-install-file.t/run.t
+++ b/test/blackbox-tests/test-cases/gen-opam-install-file.t/run.t
@@ -1,6 +1,6 @@
 stubs and js files installed
 
-  $ dune build --root stubs
+  $ dune build --root stubs | dune_cmd sanitize
   Entering directory 'stubs'
   lib: [
     "_build/install/default/lib/foo/META"
@@ -64,7 +64,7 @@ mld files are installed
 
 unwrapped libraries have the correct artifacts
 
-  $ dune build --root lib-unwrapped
+  $ dune build --root lib-unwrapped | dune_cmd sanitize
   Entering directory 'lib-unwrapped'
   lib: [
     "_build/install/default/lib/foo/META"
@@ -84,7 +84,7 @@ unwrapped libraries have the correct artifacts
 
 wrapped lib with lib interface module
 
-  $ dune build --root lib-wrapped-alias
+  $ dune build --root lib-wrapped-alias | dune_cmd sanitize
   Entering directory 'lib-wrapped-alias'
   lib: [
     "_build/install/default/lib/foo/META"
@@ -112,7 +112,7 @@ wrapped lib with lib interface module
 
 wrapped lib without lib interface module
 
-  $ dune build --root lib-wrapped-no-alias
+  $ dune build --root lib-wrapped-no-alias | dune_cmd sanitize
   Entering directory 'lib-wrapped-no-alias'
   lib: [
     "_build/install/default/lib/foo/META"
diff --git a/test/blackbox-tests/test-cases/github1549.t/run.t b/test/blackbox-tests/test-cases/github1549.t/run.t
index 1b69b9b1b14..5ed076671af 100644
--- a/test/blackbox-tests/test-cases/github1549.t/run.t
+++ b/test/blackbox-tests/test-cases/github1549.t/run.t
@@ -3,7 +3,7 @@ Reproduction case for #1549: too many parentheses in installed .dune files
   $ dune build @install --root backend
   Entering directory 'backend'
 
-  $ dune_cmd cat backend/_build/install/default/lib/dune_inline_tests/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune_cmd cat backend/_build/install/default/lib/dune_inline_tests/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
   (lang dune <version>)
   (name dune_inline_tests)
   (library
diff --git a/test/blackbox-tests/test-cases/glob-deps.t/run.t b/test/blackbox-tests/test-cases/glob-deps.t/run.t
index a399617eca8..8577438597b 100644
--- a/test/blackbox-tests/test-cases/glob-deps.t/run.t
+++ b/test/blackbox-tests/test-cases/glob-deps.t/run.t
@@ -1,2 +1,2 @@
-  $ dune build @glob
+  $ dune build @glob | dune_cmd sanitize
   foo/dune foo/foo$ext_lib foo/foo.cma foo/foo.cmxa foo/foo.cmxs foo/foo.ml
diff --git a/test/blackbox-tests/test-cases/inline_tests.t/run.t b/test/blackbox-tests/test-cases/inline_tests.t/run.t
index 6ad2006476f..e8225a75392 100644
--- a/test/blackbox-tests/test-cases/inline_tests.t/run.t
+++ b/test/blackbox-tests/test-cases/inline_tests.t/run.t
@@ -37,7 +37,7 @@ The expected behavior for the following three tests is to output nothing: the te
            run alias many-backends-choose/runtest
   backend_mbc1
 
-  $ dune runtest dune-file | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune runtest dune-file | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
            run alias dune-file/runtest
   414243
   (lang dune <version>)
@@ -77,10 +77,10 @@ The expected behavior for the following three tests is to output nothing: the te
       (echo "\n")
       (echo "let () = print_int 43;;")))))
 
-  $ dune build dune-file/foo.install && dune install foo --prefix install
+  $ dune build dune-file/foo.install && dune install foo --prefix install | dune_cmd sanitize
   Installing install/lib/foo/META
   Installing install/lib/foo/dune-package
-  Installing install/lib/foo/foo$ext_lib
+  Installing install/lib/foo/foo.a
   Installing install/lib/foo/foo.cma
   Installing install/lib/foo/foo.cmi
   Installing install/lib/foo/foo.cmt
diff --git a/test/blackbox-tests/test-cases/install-dry-run.t/run.t b/test/blackbox-tests/test-cases/install-dry-run.t/run.t
index f09869bd5bd..b581ad1c7d1 100644
--- a/test/blackbox-tests/test-cases/install-dry-run.t/run.t
+++ b/test/blackbox-tests/test-cases/install-dry-run.t/run.t
@@ -1,5 +1,5 @@
   $ dune build @install
-  $ dune install --dry-run 2>&1 | sed 's#'$(opam config var prefix)'#OPAM_PREFIX#'
+  $ dune install --dry-run 2>&1 | sed 's#'$(opam config var prefix)'#OPAM_PREFIX#' | dune_cmd sanitize
   Installing OPAM_PREFIX/lib/mylib/META
   Installing OPAM_PREFIX/lib/mylib/dune-package
   Installing OPAM_PREFIX/lib/mylib/mylib$ext_lib
@@ -45,7 +45,7 @@
   Creating directory OPAM_PREFIX/lib/mylib
   Copying _build/install/default/lib/mylib/opam to OPAM_PREFIX/lib/mylib/opam (executable: false)
 
-  $ dune uninstall --dry-run 2>&1 | sed 's#'$(opam config var prefix)'#OPAM_PREFIX#'
+  $ dune uninstall --dry-run 2>&1 | sed 's#'$(opam config var prefix)'#OPAM_PREFIX#' | dune_cmd sanitize
   Removing (if it exists) OPAM_PREFIX/lib/mylib/META
   Removing (if it exists) OPAM_PREFIX/lib/mylib/dune-package
   Removing (if it exists) OPAM_PREFIX/lib/mylib/mylib$ext_lib
diff --git a/test/blackbox-tests/test-cases/install-libdir.t/run.t b/test/blackbox-tests/test-cases/install-libdir.t/run.t
index 4405499a649..5cb1ee22483 100644
--- a/test/blackbox-tests/test-cases/install-libdir.t/run.t
+++ b/test/blackbox-tests/test-cases/install-libdir.t/run.t
@@ -4,7 +4,7 @@
 `dune install` should handle destination directories that don't exist
 
   $ dune build @install
-  $ dune install --prefix install --libdir lib
+  $ dune install --prefix install --libdir lib 2>&1 | dune_cmd sanitize
   Installing install/lib/foo/META
   Installing install/lib/foo/dune-package
   Installing install/lib/foo/foo$ext_lib
@@ -23,7 +23,7 @@
 
 If prefix is passed, the default for libdir is `$prefix/lib`:
 
-  $ dune install --prefix install --dry-run
+  $ dune install --prefix install --dry-run 2>&1 | dune_cmd sanitize
   Installing install/lib/foo/META
   Installing install/lib/foo/dune-package
   Installing install/lib/foo/foo$ext_lib
@@ -89,8 +89,8 @@ If prefix is not passed, libdir defaults to the output of `ocamlfind printconf
 destdir`:
 
   $ (export OCAMLFIND_DESTDIR=/OCAMLFIND_DESTDIR
-  >  dune install --dry-run
-  >  dune uninstall --dry-run)
+  >  dune install --dry-run 2>&1 | dune_cmd sanitize
+  >  dune uninstall --dry-run 2>&1 | dune_cmd sanitize)
   Installing /OCAMLFIND_DESTDIR/foo/META
   Installing /OCAMLFIND_DESTDIR/foo/dune-package
   Installing /OCAMLFIND_DESTDIR/foo/foo$ext_lib
@@ -175,7 +175,7 @@ destdir`:
 If only libdir is passed, binaries are installed under prefix/bin and libraries
 in libdir:
 
-  $ dune install --libdir /LIBDIR --dry-run
+  $ dune install --libdir /LIBDIR --dry-run 2>&1 | dune_cmd sanitize
   > dune uninstall --libdir /LIBDIR --dry-run
   Installing /LIBDIR/foo/META
   Installing /LIBDIR/foo/dune-package
@@ -239,7 +239,7 @@ in libdir:
   Copying _build/install/default/man/man3/another-man-page.3 to /OPAM_PREFIX/man/man3/another-man-page.3 (executable: false)
   Removing (if it exists) /LIBDIR/foo/META
   Removing (if it exists) /LIBDIR/foo/dune-package
-  Removing (if it exists) /LIBDIR/foo/foo$ext_lib
+  Removing (if it exists) /LIBDIR/foo/foo.a
   Removing (if it exists) /LIBDIR/foo/foo.cma
   Removing (if it exists) /LIBDIR/foo/foo.cmi
   Removing (if it exists) /LIBDIR/foo/foo.cmt
@@ -261,7 +261,7 @@ in libdir:
 The DESTDIR var is supported. When set, it is prepended to the prefix.
 This is the case when the prefix is implicit:
 
-  $ DESTDIR=DESTDIR dune install --dry-run
+  $ DESTDIR=DESTDIR dune install --dry-run 2>&1 | dune_cmd sanitize
   Installing DESTDIR/OPAM_PREFIX/lib/foo/META
   Installing DESTDIR/OPAM_PREFIX/lib/foo/dune-package
   Installing DESTDIR/OPAM_PREFIX/lib/foo/foo$ext_lib
@@ -325,7 +325,7 @@ This is the case when the prefix is implicit:
 
 But also when the prefix is explicit:
 
-  $ DESTDIR=DESTDIR dune install --prefix prefix --dry-run
+  $ DESTDIR=DESTDIR dune install --prefix prefix --dry-run 2>&1 | dune_cmd sanitize
   Installing DESTDIR/prefix/lib/foo/META
   Installing DESTDIR/prefix/lib/foo/dune-package
   Installing DESTDIR/prefix/lib/foo/foo$ext_lib
@@ -389,7 +389,7 @@ But also when the prefix is explicit:
 
 DESTDIR can also be passed as a command line flag.
 
-  $ dune install --destdir DESTDIR --prefix prefix --dry-run
+  $ dune install --destdir DESTDIR --prefix prefix --dry-run 2>&1 | dune_cmd sanitize
   Installing DESTDIR/prefix/lib/foo/META
   Installing DESTDIR/prefix/lib/foo/dune-package
   Installing DESTDIR/prefix/lib/foo/foo$ext_lib
diff --git a/test/blackbox-tests/test-cases/lib.t/run.t b/test/blackbox-tests/test-cases/lib.t/run.t
index 62f10b70c96..54f2e68a92e 100644
--- a/test/blackbox-tests/test-cases/lib.t/run.t
+++ b/test/blackbox-tests/test-cases/lib.t/run.t
@@ -143,10 +143,10 @@ TODO: Fix %{libexec} and %{libexec-private} variables and test them.
   > EOF
 
   $ touch external/external_library.opam
-  $ ( cd external && ../sdune build @install && ../sdune install --prefix install)
+  $ ( cd external && ../sdune build @install && ../sdune install --prefix install | dune_cmd sanitize)
   Installing install/lib/external_library/META
   Installing install/lib/external_library/dune-package
-  Installing install/lib/external_library/extlib$ext_lib
+  Installing install/lib/external_library/extlib.a
   Installing install/lib/external_library/extlib.cma
   Installing install/lib/external_library/extlib.cmi
   Installing install/lib/external_library/extlib.cmt
diff --git a/test/blackbox-tests/test-cases/no-installable-mode.t/run.t b/test/blackbox-tests/test-cases/no-installable-mode.t/run.t
index 1c08554a883..8fdc65df73c 100644
--- a/test/blackbox-tests/test-cases/no-installable-mode.t/run.t
+++ b/test/blackbox-tests/test-cases/no-installable-mode.t/run.t
@@ -17,7 +17,7 @@ message is displayed:
 
 However, it is possible to build a private one explicitly.
 
-  $ dune build --root=private --display=short myprivatelib.so
+  $ dune build --root=private --display=short myprivatelib.so 2>&1 | dune_cmd sanitize
   Entering directory 'private'
       ocamldep .myprivatelib.eobjs/myprivatelib.ml.d
         ocamlc .myprivatelib.eobjs/byte/myprivatelib.{cmi,cmo,cmt}
diff --git a/test/blackbox-tests/test-cases/output-obj.t/run.t b/test/blackbox-tests/test-cases/output-obj.t/run.t
index 45406dfbfff..8387a3cc550 100644
--- a/test/blackbox-tests/test-cases/output-obj.t/run.t
+++ b/test/blackbox-tests/test-cases/output-obj.t/run.t
@@ -1,5 +1,5 @@
   $ dune build @all
-  $ dune build @runtest
+  $ dune build @runtest 2>&1 | dune_cmd sanitize
         static alias runtest
   OK: ./static.exe
        dynamic alias runtest
diff --git a/test/blackbox-tests/test-cases/plugin-mode.t/run.t b/test/blackbox-tests/test-cases/plugin-mode.t/run.t
index 60f40b976b3..63454071fc3 100644
--- a/test/blackbox-tests/test-cases/plugin-mode.t/run.t
+++ b/test/blackbox-tests/test-cases/plugin-mode.t/run.t
@@ -79,7 +79,7 @@ Testsuite for (mode plugin).
   >   Dynlink.loadfile (Dynlink.adapt_filename "b.cma")
   > EOF
 
-  $ dune build --display short @all
+  $ dune build --display short @all 2>&1 | dune_cmd sanitize
       ocamldep foo/.foo.objs/foo.ml.d
       ocamldep $ext_lib.eobjs/a.ml.d
       ocamldep foo/.bar.objs/bar.ml.d
diff --git a/test/blackbox-tests/test-cases/re-exported-deps.t/run.t b/test/blackbox-tests/test-cases/re-exported-deps.t/run.t
index eaa080c09c4..ab3ed91c051 100644
--- a/test/blackbox-tests/test-cases/re-exported-deps.t/run.t
+++ b/test/blackbox-tests/test-cases/re-exported-deps.t/run.t
@@ -7,7 +7,7 @@ transtive deps expressed in the dune-package
 
   $ dune build @install --root transitive
   Entering directory 'transitive'
-  $ dune_cmd cat transitive/_build/install/default/lib/pkg/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune_cmd cat transitive/_build/install/default/lib/pkg/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
   (lang dune <version>)
   (name pkg)
   (library
diff --git a/test/blackbox-tests/test-cases/reason.t/run.t b/test/blackbox-tests/test-cases/reason.t/run.t
index 90529b0b823..dcff46d2916 100644
--- a/test/blackbox-tests/test-cases/reason.t/run.t
+++ b/test/blackbox-tests/test-cases/reason.t/run.t
@@ -1,55 +1,26 @@
-  $ dune build @runtest @install-file
-  lib: [
-    "_build/install/default/lib/rlib/META"
-    "_build/install/default/lib/rlib/bar.mli"
+Tests for reason
+
+Build and run a reason binary:
+
+  $ dune build @runtest
+          rbin alias runtest
+  Cppome
+  hello world
+  Bar
+  Foo
+
+We make sure to install reason source files:
+
+  $ dune build @install-file 2>&1 | grep ".re"
     "_build/install/default/lib/rlib/bar.re"
     "_build/install/default/lib/rlib/cppome.re"
     "_build/install/default/lib/rlib/cppome.rei"
-    "_build/install/default/lib/rlib/dune-package"
-    "_build/install/default/lib/rlib/foo.ml"
     "_build/install/default/lib/rlib/foo.rei"
     "_build/install/default/lib/rlib/hello.re"
     "_build/install/default/lib/rlib/hello.rei"
-    "_build/install/default/lib/rlib/opam"
     "_build/install/default/lib/rlib/pped.re"
     "_build/install/default/lib/rlib/pped.rei"
-    "_build/install/default/lib/rlib/rlib$ext_lib"
-    "_build/install/default/lib/rlib/rlib.cma"
-    "_build/install/default/lib/rlib/rlib.cmi"
-    "_build/install/default/lib/rlib/rlib.cmt"
-    "_build/install/default/lib/rlib/rlib.cmx"
-    "_build/install/default/lib/rlib/rlib.cmxa"
-    "_build/install/default/lib/rlib/rlib.cmxs"
-    "_build/install/default/lib/rlib/rlib.ml"
-    "_build/install/default/lib/rlib/rlib__Bar.cmi"
-    "_build/install/default/lib/rlib/rlib__Bar.cmt"
-    "_build/install/default/lib/rlib/rlib__Bar.cmti"
-    "_build/install/default/lib/rlib/rlib__Bar.cmx"
-    "_build/install/default/lib/rlib/rlib__Cppome.cmi"
-    "_build/install/default/lib/rlib/rlib__Cppome.cmt"
-    "_build/install/default/lib/rlib/rlib__Cppome.cmti"
-    "_build/install/default/lib/rlib/rlib__Cppome.cmx"
-    "_build/install/default/lib/rlib/rlib__Foo.cmi"
-    "_build/install/default/lib/rlib/rlib__Foo.cmt"
-    "_build/install/default/lib/rlib/rlib__Foo.cmti"
-    "_build/install/default/lib/rlib/rlib__Foo.cmx"
-    "_build/install/default/lib/rlib/rlib__Hello.cmi"
-    "_build/install/default/lib/rlib/rlib__Hello.cmt"
-    "_build/install/default/lib/rlib/rlib__Hello.cmti"
-    "_build/install/default/lib/rlib/rlib__Hello.cmx"
-    "_build/install/default/lib/rlib/rlib__Pped.cmi"
-    "_build/install/default/lib/rlib/rlib__Pped.cmt"
-    "_build/install/default/lib/rlib/rlib__Pped.cmti"
-    "_build/install/default/lib/rlib/rlib__Pped.cmx"
-  ]
-  bin: [
     "_build/install/default/bin/refmt"
-  ]
-          rbin alias runtest
-  Cppome
-  hello world
-  Bar
-  Foo
 
 virtual libraries in reason
   $ PATH="_build/install/default/bin:$PATH" dune build --root vlib-impl @all
diff --git a/test/blackbox-tests/test-cases/virtual-libraries/dune-package-info/run.t b/test/blackbox-tests/test-cases/virtual-libraries/dune-package-info/run.t
index 27af45e3730..77b0ed39631 100644
--- a/test/blackbox-tests/test-cases/virtual-libraries/dune-package-info/run.t
+++ b/test/blackbox-tests/test-cases/virtual-libraries/dune-package-info/run.t
@@ -1,5 +1,5 @@
 Include variants and implementation information in dune-package
-  $ dune build | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune build | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
   (lang dune <version>)
   (name foo)
   (library
diff --git a/test/blackbox-tests/test-cases/virtual-libraries/install-file/run.t b/test/blackbox-tests/test-cases/virtual-libraries/install-file/run.t
index 7a80441dc39..1ae549f6974 100644
--- a/test/blackbox-tests/test-cases/virtual-libraries/install-file/run.t
+++ b/test/blackbox-tests/test-cases/virtual-libraries/install-file/run.t
@@ -1,5 +1,5 @@
 Install files for implementations and virtual libs have all the artifacts:
-  $ dune build
+  $ dune build 2>&1 | dune_cmd sanitize
   lib: [
     "_build/install/default/lib/vlib/META"
     "_build/install/default/lib/vlib/dune-package"
diff --git a/test/blackbox-tests/test-cases/virtual-libraries/vlib-default-impl/run.t b/test/blackbox-tests/test-cases/virtual-libraries/vlib-default-impl/run.t
index 949e2ee06f8..d4586789088 100644
--- a/test/blackbox-tests/test-cases/virtual-libraries/vlib-default-impl/run.t
+++ b/test/blackbox-tests/test-cases/virtual-libraries/vlib-default-impl/run.t
@@ -17,7 +17,7 @@ Basic sample selecting implementation according to default library.
 Check that default implementation data is installed in the dune package file.
   $ dune build --root dune-package
   Entering directory 'dune-package'
-  $ dune_cmd cat dune-package/_build/install/default/lib/a/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/"
+  $ dune_cmd cat dune-package/_build/install/default/lib/a/dune-package | sed "s/(lang dune .*)/(lang dune <version>)/" | dune_cmd sanitize
   (lang dune <version>)
   (name a)
   (library
diff --git a/test/blackbox-tests/utils/dune b/test/blackbox-tests/utils/dune
index f14ceaf836c..457c2b723d0 100644
--- a/test/blackbox-tests/utils/dune
+++ b/test/blackbox-tests/utils/dune
@@ -1,3 +1,3 @@
 (executable
  (name dune_cmd)
- (libraries stdune dune-private-libs.dune_re))
+ (libraries stdune dune-private-libs.dune_re dune-configurator))
diff --git a/test/blackbox-tests/utils/dune_cmd.ml b/test/blackbox-tests/utils/dune_cmd.ml
index 8a40581c5aa..4862a9b4450 100644
--- a/test/blackbox-tests/utils/dune_cmd.ml
+++ b/test/blackbox-tests/utils/dune_cmd.ml
@@ -88,6 +88,57 @@ module Expand_lines = struct
   let () = register name of_args run
 end
 
+module Sanitizer = struct
+  module Configurator = Configurator.V1
+
+  let make_ext_replace config =
+    let tbl =
+      List.filter_map [ "ext_exe"; "ext_dll"; "ext_asm"; "ext_lib"; "ext_obj" ]
+        ~f:(fun var ->
+          match Configurator.ocaml_config_var config var with
+          | Some "" -> None
+          | Some s -> Some (s, "$" ^ var)
+          | None -> (
+            match (var, Configurator.ocaml_config_var config "system") with
+            | "ext_exe", Some "Win32" -> Some (".exe", var)
+            | _ -> None ))
+    in
+    let re =
+      Re.(
+        compile
+          (seq
+             [ diff any (char '/')
+             ; alt (List.map tbl ~f:(fun (s, _) -> str s))
+             ; eow
+             ]))
+    in
+    let map = String.Map.of_list_reduce tbl ~f:(fun _ x -> x) in
+    fun s ->
+      Re.replace re s ~f:(fun g ->
+          let s = Re.Group.get g 0 in
+          sprintf "%c%s" s.[0] (String.Map.find_exn map (String.drop s 1)))
+
+  let name = "sanitize"
+
+  let of_args = function
+    | [] -> ()
+    | _ -> raise (Arg.Bad "Usage: dune_cmd sanitize takes no arguments")
+
+  let run () =
+    let config = Configurator.create "sanitizer" in
+    let sanitize = make_ext_replace config in
+    let rec loop () =
+      match input_line stdin with
+      | exception End_of_file -> ()
+      | line ->
+        print_endline (sanitize line);
+        loop ()
+    in
+    loop ()
+
+  let () = register name of_args run
+end
+
 let () =
   let name, args =
     match Array.to_list Sys.argv with