unikernel/duniverse/dune_/test/blackbox-tests/test-cases/env/env-tracking.t/a.ml

@@ -0,0 +1,8 @@
+let print_var k =
+  match Sys.getenv k with
+  | v -> Printf.printf "%s = %S\n" k v
+  | exception Not_found -> Printf.printf "%s is not set\n" k
+
+let () =
+  print_var "X";
+  print_var "Y"

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/env/env-tracking.t/dune

@@ -0,0 +1,11 @@
+(executable
+ (name a))
+
+(alias
+ (name without_dep)
+ (action (run ./a.exe)))
+
+(alias
+ (name with_dep)
+ (deps (env_var X))
+ (action (run ./a.exe)))

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/env/env-tracking.t/dune-project

@@ -0,0 +1 @@
+(lang dune 1.1)

unikernel/duniverse/dune_/test/blackbox-tests/test-cases/env/env-tracking.t/run.t

@@ -0,0 +1,21 @@
+Aliases without a (env) dependency are not rebuilt when the environment
+changes:
+
+  $ dune build @without_dep
+  X is not set
+  Y is not set
+  $ X=x dune build @without_dep
+
+But if there is a dependency, the alias gets rebuilt:
+
+  $ dune build @with_dep
+  X is not set
+  Y is not set
+  $ X=x dune build @with_dep
+  X = "x"
+  Y is not set
+
+This only happens for tracked variables:
+
+  $ dune build @with_dep
+  $ Y=y dune build @with_dep