unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/alias-cycle.t

@@ -0,0 +1,49 @@
+In this test we check a cycle when a library depends on a genrated source file which in
+turn depends on the inline-test-name alias of the inline tests of the library.
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.18)
+  > EOF
+
+  $ cat >test.ml <<EOF
+  > (*TEST: assert (1 = 2) *)
+  > EOF
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_simple)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (run sed "s/(\\\\*TEST:\\\\(.*\\\\)\\\\*)/let () = if \\"%{inline_tests}\\" = \\"enabled\\" then \\\\1;;/" %{impl-files}))))
+  > 
+  > (library
+  >  (name foo_simple)
+  >  (inline_tests (backend backend_simple)))
+  > 
+  > (rule
+  >  (deps
+  >   (alias runtest-foo_simple))
+  >  (action
+  >   (with-outputs-to bar.ml
+  >    (echo "let message = \"Hello world\""))))
+  > EOF
+
+This kind of cycle has a difficult to understand error message.
+  $ dune build 2>&1 | grep -vwE "sed"
+  File "dune", lines 7-9, characters 0-69:
+  7 | (library
+  8 |  (name foo_simple)
+  9 |  (inline_tests (backend backend_simple)))
+  Error: Dependency cycle between:
+     _build/default/.foo_simple.objs/foo_simple__Bar.impl.all-deps
+  -> _build/default/.foo_simple.objs/byte/foo_simple__Bar.cmi
+  -> _build/default/.foo_simple.inline-tests/.t.eobjs/native/dune__exe__Main.cmx
+  -> _build/default/.foo_simple.inline-tests/inline-test-runner.exe
+  -> alias runtest-foo_simple in dune:9
+  -> _build/default/bar.ml
+  -> _build/default/.foo_simple.objs/foo_simple__Bar.impl.d
+  -> _build/default/.foo_simple.objs/foo_simple__Bar.impl.all-deps
+  -> required by _build/default/.foo_simple.objs/byte/foo_simple__Bar.cmo
+  -> required by _build/default/foo_simple.cma
+  -> required by alias all
+  -> required by alias default

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/concurrent-fail.t

@@ -0,0 +1,53 @@
+Failing inline tests shouldn't hinder the diffing or promotion of other tests.
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.7)
+  > EOF
+
+  $ cat > dune << EOF
+  > (library
+  >  (name test)
+  >  (inline_tests)
+  >  (wrapped false)
+  >  (preprocess (pps ppx_expect)))
+  > EOF
+
+Here is a broken test in it's own file.
+  $ cat > print.ml << EOF
+  > let f = Printf.printf
+  > EOF
+
+We have two files with an inline test. Both tests should fail.
+  $ cat > test1.ml << EOF
+  > let%expect_test "test1" = Print.f "hello"; [%expect {| |}]
+  > EOF
+
+  $ cat > test2.ml << EOF
+  > let%expect_test "test1" = Print.f "hello"; [%expect {| |}]
+  > EOF
+
+  $ dune test
+  File "test1.ml", line 1, characters 0-0:
+  Error: Files _build/default/test1.ml and _build/default/test1.ml.corrected
+  differ.
+  File "test2.ml", line 1, characters 0-0:
+  Error: Files _build/default/test2.ml and _build/default/test2.ml.corrected
+  differ.
+  [1]
+
+  $ dune promote
+  Promoting _build/default/test1.ml.corrected to test1.ml.
+  Promoting _build/default/test2.ml.corrected to test2.ml.
+
+  $ cat test1.ml
+  let%expect_test "test1" = Print.f "hello"; [%expect {| hello |}]
+  $ cat test2.ml
+  let%expect_test "test1" = Print.f "hello"; [%expect {| hello |}]
+
+We can see that running test again succeed.
+  $ dune test
+  $ dune promote
+  $ cat test1.ml
+  let%expect_test "test1" = Print.f "hello"; [%expect {| hello |}]
+  $ cat test2.ml
+  let%expect_test "test1" = Print.f "hello"; [%expect {| hello |}]

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune

@@ -0,0 +1,13 @@
+(cram
+ (applies_to github6607 reason-expect concurrent-fail)
+ (deps
+  (package ppx_expect)))
+
+(cram
+ (applies_to reason-expect)
+ (deps %{bin:refmt}))
+
+(cram
+ (applies_to github6607)
+ (deps
+  (package stdune)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune-file.t/dune-file-user/dune

@@ -0,0 +1,3 @@
+(library
+ (name foo_tests)
+ (inline_tests (backend foo)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune-file.t/dune-file-user/dune-project

@@ -0,0 +1 @@
+(lang dune 1.0)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune-file.t/dune-file/dune

@@ -0,0 +1,19 @@
+(library
+ (name foo)
+ (public_name foo)
+ (modules ())
+ (inline_tests.backend
+  (runner_libraries str)
+  (generate_runner
+   (progn
+    (echo "let () = print_int 41")
+    (echo "\n")
+    (echo "let () = print_int 42")
+    (echo "\n")
+    (echo "let () = print_int 43;;")))
+  (flags inline-test-runner %{library-name}
+          -source-tree-root %{workspace_root} -diff-cmd -)))
+
+(library
+ (name foo_tests)
+ (inline_tests (backend foo)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune-file.t/dune-file/dune-project

@@ -0,0 +1 @@
+(lang dune 1.0)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/dune-file.t/run.t

@@ -0,0 +1,31 @@
+This test makes sure that inline_tests backends are functional when they are
+externally installed.
+
+First we build and use the backend locally:
+
+  $ dune runtest dune-file
+  414243
+
+Then we install the backend and check that the "inline_tests.backend"
+field is properly generated in the installed `dune-package` file:
+
+  $ dune build dune-file/foo.install
+  $ dune install foo --prefix _install
+  $ grep -A8 inline_tests.backend _install/lib/foo/dune-package
+   (inline_tests.backend
+    (runner_libraries str)
+    (flags
+     inline-test-runner
+     %{library-name}
+     -source-tree-root
+     %{workspace_root}
+     -diff-cmd
+     -)
+
+Now we make sure that we can use the backend when it's available as an external
+package:
+
+  $ export OCAMLPATH=$PWD/_install/lib; dune runtest --root dune-file-user
+  Entering directory 'dune-file-user'
+  414243
+  Leaving directory 'dune-file-user'

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/enabled-if.t

@@ -0,0 +1,22 @@
+enabled_if inside the inline_tests field in the library stanza
+
+  $ mkdir tmp && cd tmp
+  $ cat >dune-project <<EOF
+  > (lang dune 3.0)
+  > EOF
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_mbc)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo "print_endline \"backend_mbc\""))))
+  > 
+  > (library
+  >  (name foo_mbc)
+  >  (inline_tests
+  >   (enabled_if false)
+  >   (backend backend_mbc))
+  >  (libraries backend_mbc))
+  > EOF
+
+  $ dune runtest

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/executable-flags.t/run.t

@@ -0,0 +1,17 @@
+This test ensures that compilation fails when an invalid option is supplied
+to flags field in executable field in inline_tests field.
+
+First, we pass a valid option to flags field expecting compilation
+to be successful.
+
+  $ dune runtest valid_options --root ./test-project
+  Entering directory 'test-project'
+  backend_foo
+  Leaving directory 'test-project'
+
+Lastly, we pass an invalid option to flags field expecting compilation
+to fail.
+
+  $ output=$(dune runtest invalid_options --root ./test-project 2>&1); result=$?; (echo $output | grep -o "unknown option '-option-that-is-not-accepted-by-ocaml'."); (exit $result)
+  unknown option '-option-that-is-not-accepted-by-ocaml'.
+  [1]

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/executable-flags.t/test-project/dune

@@ -0,0 +1,6 @@
+(library
+ (name backend_foo)
+ (modules ())
+ (inline_tests.backend
+  (generate_runner
+   (echo "let () = print_endline \"backend_foo\""))))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/executable-flags.t/test-project/dune-project

@@ -0,0 +1 @@
+(lang dune 2.8)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/executable-flags.t/test-project/invalid_options/dune

@@ -0,0 +1,6 @@
+(library
+ (name invalid_option_test)
+ (inline_tests
+  (backend backend_foo)
+  (executable
+   (flags -option-that-is-not-accepted-by-ocaml))))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/executable-flags.t/test-project/valid_options/dune

@@ -0,0 +1,6 @@
+(library
+ (name valid_option_test)
+ (inline_tests
+  (backend backend_foo)
+  (executable
+   (flags -nolabels))))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/github6607.t

@@ -0,0 +1,58 @@
+This shows that the test suite is impacted by CLICOLOR_FORCE=1 (#6607).
+This environment variable should only impact the output of dune, not behavior
+visible from within the test suite.
+
+  $ cat > dune-project << EOF
+  > (lang dune 1.0)
+  > EOF
+
+  $ cat > dune << EOF
+  > (library
+  >  (name l)
+  >  (libraries stdune)
+  >  (preprocess (pps ppx_expect))
+  >  (inline_tests))
+  > EOF
+
+  $ cat > l.ml << EOF
+  > open[@ocaml.alert "-unstable"] Stdune
+  > 
+  > let%expect_test _ =
+  >   User_message.print (User_error.make []);
+  >   [%expect]
+  > EOF
+
+When running with `CLICOLOR_FORCE=0`, no escape codes are present in the output
+string. But when it is set to `1`, escape codes are present.
+Remarks:
+- it is necessary to pipe into `tr` to see the difference because otherwise these
+escape codes are stripped by cram, and it is necessary
+- it is necessary to call `dune clean` because `dune` does not know that the
+runtest depends on `CLICOLOR_FORCE`.
+
+The expected outcome would be that both of these runs output the same corrected
+file.
+
+  $ CLICOLOR_FORCE=0 dune runtest --auto-promote
+  File "l.ml", line 1, characters 0-0:
+  Error: Files _build/default/l.ml and _build/default/l.ml.corrected differ.
+  Promoting _build/default/l.ml.corrected to l.ml.
+  [1]
+  $ < l.ml tr '\033' '?'
+  open[@ocaml.alert "-unstable"] Stdune
+  
+  let%expect_test _ =
+    User_message.print (User_error.make []);
+    [%expect {| Error: |}]
+  $ dune clean
+  $ CLICOLOR_FORCE=1 dune runtest --auto-promote
+  File "l.ml", line 1, characters 0-0:
+  Error: Files _build/default/l.ml and _build/default/l.ml.corrected differ.
+  Promoting _build/default/l.ml.corrected to l.ml.
+  [1]
+  $ < l.ml tr '\033' '?'
+  open[@ocaml.alert "-unstable"] Stdune
+  
+  let%expect_test _ =
+    User_message.print (User_error.make []);
+    [%expect {| ?[1;31mError?[0m: |}]

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/many-backends-choose.t

@@ -0,0 +1,24 @@
+  $ cat >dune-project <<EOF
+  > (lang dune 2.6)
+  > EOF
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_mbc1)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo "print_endline \"backend_mbc1\""))))
+  > 
+  > (library
+  >  (name backend_mbc2)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo "print_endline \"backend_mbc2\""))))
+  > 
+  > (library
+  >  (name foo_mbc)
+  >  (inline_tests (backend backend_mbc1))
+  >  (libraries backend_mbc1 backend_mbc2))
+  > EOF
+
+  $ dune runtest
+  backend_mbc1

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/missing-backend.t

@@ -0,0 +1,15 @@
+  $ cat >dune-project <<EOF
+  > (lang dune 2.6)
+  > EOF
+  $ cat >dune <<EOF
+  > (library
+  >  (name foo_mb)
+  >  (inline_tests))
+  > EOF
+
+  $ dune runtest
+  File "dune", line 3, characters 1-15:
+  3 |  (inline_tests))
+       ^^^^^^^^^^^^^^
+  Error: No inline tests backend found.
+  [1]

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/multiple-inline-tests.t

@@ -0,0 +1,31 @@
+Test for multiple libraries with inline_tests set in the same directory
+
+  $ cat >dune-project <<EOF
+  > (lang dune 2.6)
+  > EOF
+
+Create a dummy backend and two libraries with inline_tests
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_simple)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo "print_endline \"test\""))))
+  > 
+  > (library
+  >  (name foo_simple1)
+  >  (modules ())
+  >  (inline_tests (backend backend_simple)))
+  > 
+  > (library
+  >  (name foo_simple2)
+  >  (modules ())
+  >  (inline_tests (backend backend_simple)))
+  > EOF
+
+try to run them:
+
+  $ env -u OCAMLRUNPARAM dune runtest
+  test
+  test

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/backend/dune

@@ -0,0 +1,19 @@
+(library
+ (name fake_backend_1)
+ (modules ())
+ (inline_tests.backend
+  (runner_libraries fake_backend_runner)
+  (generate_runner (echo "let () = Fake_backend_runner.run ();;"))
+  (flags "--libname" %{library-name})))
+
+(library
+ (name fake_backend_2)
+ (modules ())
+ (inline_tests.backend
+  (extends fake_backend_1)
+  (list_partitions_flags ("--libname" %{library-name} "--list-partitions"))
+  (flags ("--partition" %{partition}))))
+
+(library
+ (name fake_backend_runner)
+ (modules fake_backend_runner))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/backend/fake_backend_runner.ml

@@ -0,0 +1,49 @@
+module StringSet = Set.Make(String)
+
+let usage_msg = ""
+
+let list_partitions = ref false
+
+let partition = ref ""
+
+let libname = ref ""
+
+let anon_fun _ = ()
+
+let speclist =
+  [ ("--libname", Arg.Set_string libname, "libname")
+  ; ("--partition", Arg.Set_string partition, "partition")
+  ; ("--list-partitions", Arg.Set list_partitions, "list partitions")
+  ]
+
+type t =
+  { libname : string
+  ; partition : string
+  ; name : string
+  ; run : unit -> unit
+  }
+
+let tests = ref []
+
+let register ~libname ~partition name run =
+  tests := { libname; partition; name; run } :: !tests
+
+let run () =
+  Arg.parse speclist anon_fun usage_msg;
+  if !libname = "" then failwith "Should specify libname";
+  if !list_partitions then
+    let partitions =
+      List.fold_left
+        (fun acc t -> if !libname = t.libname then StringSet.add t.partition acc else acc)
+        StringSet.empty !tests
+    in
+    StringSet.iter print_endline partitions;
+  List.iter
+    (fun t ->
+      if t.libname = !libname && t.partition = !partition then (
+        Printf.printf "Running %s\n" t.name;
+        try
+          t.run ();
+          Printf.printf "Ok\n"
+        with e -> Printf.printf "Error: %s\n" (Printexc.to_string e)))
+    (List.rev !tests)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/dune-project

@@ -0,0 +1 @@
+(lang dune 3.8)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/run.t

@@ -0,0 +1,30 @@
+First, build silently to avoid some noise
+
+  $ dune build
+
+See that `test1/runtest`, which uses `fake_backend_1, only runs one inline test runner
+
+  $ dune build --display short @test1/runtest 2>&1 | grep alias
+  inline-test-runner alias test1/runtest-test_lib1
+
+See that `test2/runtest`, which uses `fake_backend_2`, runs one inline test runner per partition
+
+  $ dune build --display short @test2/runtest 2>&1 | grep alias
+  inline-test-runner alias test2/runtest-test_lib2
+  inline-test-runner alias test2/runtest-test_lib2
+  inline-test-runner alias test2/runtest-test_lib2
+
+See that we indeed have 3 partitions
+
+  $ cat _build/default/test2/.test_lib2.inline-tests/partitions-best
+  p1
+  p2
+  p3
+
+
+  $ dune build --display short @test3/runtest 2>&1 | grep alias
+  [1]
+
+See that we have no partition.
+
+  $ cat _build/default/test3/.test_lib3.inline-tests/partitions-best

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test1/dune

@@ -0,0 +1,4 @@
+(library
+ (name test_lib1)
+ (libraries fake_backend_runner)
+ (inline_tests (backend fake_backend_1)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test1/test_lib1.ml

@@ -0,0 +1,19 @@
+let () =
+  Fake_backend_runner.register ~libname:"test_lib" ~partition:"p1" "first test"
+    (fun () -> assert true)
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib" ~partition:"p1" "second test"
+    (fun () -> ()    )
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib" ~partition:"p2" "first test"
+    (fun () -> ())
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib" ~partition:"p3" "first test"
+    (fun () -> failwith "This failure is expected")
+
+let () =
+  Fake_backend_runner.register ~libname:"other_lib" ~partition:"p1"
+    "second test" (fun () -> assert false)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test2/dune

@@ -0,0 +1,4 @@
+(library
+ (name test_lib2)
+ (libraries fake_backend_runner)
+ (inline_tests (backend fake_backend_2)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test2/test_lib2.ml

@@ -0,0 +1,23 @@
+let () =
+  Fake_backend_runner.register ~libname:"test_lib2" ~partition:"p1" "first test"
+    (fun () -> assert true)
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib2" ~partition:"p1" "second test"
+    (fun () -> ()    )
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib2" ~partition:"p2" "first test"
+    (fun () -> ())
+
+let () =
+  Fake_backend_runner.register ~libname:"test_lib2" ~partition:"p3" "first test"
+    (fun () -> failwith "This failure is expected")
+
+let () =
+  Fake_backend_runner.register ~libname:"other_lib" ~partition:"p1"
+    "second test" (fun () -> assert false)
+
+let () =
+  Fake_backend_runner.register ~libname:"other_lib" ~partition:"pn"
+    "second test" (fun () -> assert false)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test3/dune

@@ -0,0 +1,4 @@
+(library
+ (name test_lib3)
+ (libraries fake_backend_runner)
+ (inline_tests (backend fake_backend_2)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/parallel.t/test3/test_lib3.ml

@@ -0,0 +1,3 @@
+let () =
+  Fake_backend_runner.register ~libname:"other_lib" ~partition:"p1"
+    "second test" (fun () -> assert false)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/reason-expect.t/run.t

@@ -0,0 +1,28 @@
+Testing the interaction of reason syntax and ppx expect
+
+  $ cat > dune << EOF
+  > (library
+  >  (name test)
+  >  (inline_tests)
+  >  (preprocess (pps ppx_expect)))
+  > EOF
+
+  $ cat > test.re << EOF
+  > let%expect_test _ =
+  >   print_endline("Hello, world!");
+  >   [%expect {| |}]
+  > EOF
+
+In https://github.com/ocaml/dune/issues/7930 there is an issue where reason
+syntax and ppx_expect break at dune lang 3.3 due to the sandboxing of ppx.
+
+  $ cat > dune-project << EOF
+  > (lang dune 3.9)
+  > EOF
+  $ dune test 2>&1 | head -n 6
+  File "dune", line 3, characters 1-15:
+  3 |  (inline_tests)
+       ^^^^^^^^^^^^^^
+  Fatal error: exception Invalid_argument("pos + len past end: 0 + 79 > 72")
+  Raised at Stdlib.invalid_arg in file "stdlib.ml", line 30, characters 20-45
+  Called from Base__Ordered_collection_common0.check_pos_len_exn in file "src/ordered_collection_common0.ml" (inlined), line 31, characters 7-53

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/simple.t

@@ -0,0 +1,66 @@
+  $ cat >test.ml <<EOF
+  > (*TEST: assert (1 = 2) *)
+  > EOF
+
+  $ cat >dune-project <<EOF
+  > (lang dune 2.6)
+  > EOF
+
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_simple)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (run sed "s/(\\\\*TEST:\\\\(.*\\\\)\\\\*)/let () = if \\"%{inline_tests}\\" = \\"enabled\\" then \\\\1;;/" %{impl-files}))))
+  > 
+  > (library
+  >  (name foo_simple)
+  >  (inline_tests (backend backend_simple)))
+  > 
+  > (env
+  >  (ignore-inline-tests (inline_tests ignored))
+  >  (enable-inline-tests (inline_tests enabled))
+  >  (disable-inline-tests (inline_tests disabled)))
+  > EOF
+
+  $ env -u OCAMLRUNPARAM dune runtest
+  File "dune", line 9, characters 1-40:
+  9 |  (inline_tests (backend backend_simple)))
+       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  Fatal error: exception File ".foo_simple.inline-tests/main.ml-gen", line 1, characters 40-46: Assertion failed
+  [1]
+
+Inline tests also generate an alias
+  $ dune build @runtest-foo_simple
+  File "dune", line 9, characters 1-40:
+  9 |  (inline_tests (backend backend_simple)))
+       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  Fatal error: exception File ".foo_simple.inline-tests/main.ml-gen", line 1, characters 40-46: Assertion failed
+  [1]
+
+Make sure building both aliases doesn't build both
+  $ dune build @runtest @lib-foo_simple
+  Error: Alias "lib-foo_simple" specified on the command line is empty.
+  It is not defined in . or any of its descendants.
+  File "dune", line 9, characters 1-40:
+  9 |  (inline_tests (backend backend_simple)))
+       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  Fatal error: exception File ".foo_simple.inline-tests/main.ml-gen", line 1, characters 40-46: Assertion failed
+  [1]
+This test demonstrates that the action is being run once
+  $ cat _build/log | sed 's/\$ //g' | grep inline-test-runner 
+  (cd _build/default && .foo_simple.inline-tests/inline-test-runner.exe)
+
+The expected behavior for the following three tests is to output nothing: the tests are disabled or ignored.
+  $ env -u OCAMLRUNPARAM dune runtest --profile release
+
+  $ env -u OCAMLRUNPARAM dune runtest --profile disable-inline-tests
+
+  $ env -u OCAMLRUNPARAM dune runtest --profile ignore-inline-tests
+
+  $ env -u OCAMLRUNPARAM dune runtest --profile enable-inline-tests
+  File "dune", line 9, characters 1-40:
+  9 |  (inline_tests (backend backend_simple)))
+       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  Fatal error: exception File ".foo_simple.inline-tests/main.ml-gen", line 1, characters 40-46: Assertion failed
+  [1]

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/inline_tests/too-many-backends.t

@@ -0,0 +1,30 @@
+  $ cat >dune-project <<EOF
+  > (lang dune 2.6)
+  > EOF
+  $ cat >dune <<EOF
+  > (library
+  >  (name backend_tmb1)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo foo))))
+  > 
+  > (library
+  >  (name backend_tmb2)
+  >  (modules ())
+  >  (inline_tests.backend
+  >   (generate_runner (echo foo))))
+  > 
+  > (library
+  >  (name foo_tmb)
+  >  (inline_tests)
+  >  (libraries backend_tmb1 backend_tmb2))
+  > EOF
+
+  $ dune runtest
+  File "dune", line 15, characters 1-15:
+  15 |  (inline_tests)
+        ^^^^^^^^^^^^^^
+  Error: Too many independent inline tests backends found:
+  - "backend_tmb1" in _build/default
+  - "backend_tmb2" in _build/default
+  [1]