diff --git a/e2e/non_unique_fan_out/e2e_test.go b/e2e/non_unique_fan_out/e2e_test.go
index 88713493..5d9ce0be 100644
--- a/e2e/non_unique_fan_out/e2e_test.go
+++ b/e2e/non_unique_fan_out/e2e_test.go
@@ -15,10 +15,10 @@ func Test(t *testing.T) {
 	out, err := cmd.CombinedOutput()
 	require.NoError(t, err)
 
-	require.Equal(
+	require.Contains(
 		t,
-		"main/main.neva:4:10: port 'in:start' is used twice\n",
 		string(out),
+		"main/main.neva:2:10: port 'in:start' is used twice\n",
 	)
 
 	require.Equal(t, 0, cmd.ProcessState.ExitCode())
diff --git a/e2e/non_unique_fan_out/main/main.neva b/e2e/non_unique_fan_out/main/main.neva
index 8d12ae4b..302dfb03 100644
--- a/e2e/non_unique_fan_out/main/main.neva
+++ b/e2e/non_unique_fan_out/main/main.neva
@@ -1,5 +1,3 @@
-import { io }
-
 def Main(start any) (stop any) {
 	[:start, :start] -> :stop
 }
\ No newline at end of file
diff --git a/e2e/order_dependend_with_arr_inport/main/main.neva b/e2e/order_dependend_with_arr_inport/main/main.neva
index 0646f023..88ba2d57 100644
--- a/e2e/order_dependend_with_arr_inport/main/main.neva
+++ b/e2e/order_dependend_with_arr_inport/main/main.neva
@@ -1,3 +1,5 @@
+import { fmt }
+
 const l list<int> = [1, 2, 3]
 
 def Main(start) (stop) {
diff --git a/e2e/print_float/main/main.neva b/e2e/print_float/main/main.neva
index 3bc02bf7..79a19906 100644
--- a/e2e/print_float/main/main.neva
+++ b/e2e/print_float/main/main.neva
@@ -1,3 +1,5 @@
+import { fmt }
+
 const x float = 42
 
 def Main(start) (stop) {
diff --git a/e2e/regex_submatch_verbose/main/main.neva b/e2e/regex_submatch_verbose/main/main.neva
index 4440e040..5c842aeb 100644
--- a/e2e/regex_submatch_verbose/main/main.neva
+++ b/e2e/regex_submatch_verbose/main/main.neva
@@ -1,4 +1,4 @@
-import { regexp }
+import { regexp, fmt }
 
 def Main(start) (stop) {
     fmt.Println, regexp.Submatch, Panic
diff --git a/e2e/run_cli_not_from_module_root/foo/bar/main.neva b/e2e/run_cli_not_from_module_root/foo/bar/main.neva
index 82467d99..f649d4f6 100644
--- a/e2e/run_cli_not_from_module_root/foo/bar/main.neva
+++ b/e2e/run_cli_not_from_module_root/foo/bar/main.neva
@@ -1,3 +1,5 @@
+import { fmt }
+
 def Main(start) (stop) {
     fmt.Println
     ---
diff --git a/e2e/simple_fan_out/main/main.neva b/e2e/simple_fan_out/main/main.neva
index 592ccde1..0e7915a0 100644
--- a/e2e/simple_fan_out/main/main.neva
+++ b/e2e/simple_fan_out/main/main.neva
@@ -1,4 +1,4 @@
-import { time }
+import { time, fmt }
 
 def Main(start) (stop) {
     p1 fmt.Println
diff --git a/e2e/slow_iteration_with_for/main/main.neva b/e2e/slow_iteration_with_for/main/main.neva
index fe4504ee..8b07efcc 100644
--- a/e2e/slow_iteration_with_for/main/main.neva
+++ b/e2e/slow_iteration_with_for/main/main.neva
@@ -2,7 +2,7 @@
 // https://github.com/nevalang/neva/issues/575
 // all elements of the array must be printed befofe program terminate
 
-import { time }
+import { time, fmt }
 
 const lst list<int> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
 
@@ -13,8 +13,8 @@ def Main(start) (stop) {
 }
 
 def Slow(data int) (sig any) {
-    time.Delay
-    fmt.Println
+    time.Delay<int>
+    fmt.Println<int>
     ---
     :data -> delay:data
     $time.second -> delay:dur
diff --git a/e2e/slow_iteration_with_map/main/main.neva b/e2e/slow_iteration_with_map/main/main.neva
index 26c6e018..de6660fc 100644
--- a/e2e/slow_iteration_with_map/main/main.neva
+++ b/e2e/slow_iteration_with_map/main/main.neva
@@ -2,15 +2,15 @@
 // https://github.com/nevalang/neva/issues/575
 // all elements of the array must be printed befofe program terminate
 
-import { time }
+import { time, fmt }
 
 const lst list<int> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
 
 def Main(start) (stop) {
     ListToStream<int>
     Map<int, int>{Slow}
-    List
-    fmt.Println
+    List<int>
+    fmt.Println<list<int>>
     ---
     :start -> {
         $lst -> listToStream -> map -> list -> println -> :stop
diff --git a/e2e/struct_selector_on_port_addr/main/main.neva b/e2e/struct_selector_on_port_addr/main/main.neva
index df5447e8..4348ce42 100644
--- a/e2e/struct_selector_on_port_addr/main/main.neva
+++ b/e2e/struct_selector_on_port_addr/main/main.neva
@@ -1,8 +1,10 @@
+import { fmt }
+
 def Main(start) (stop) {
     Foo, fmt.Println<int>
     ---
     :start -> foo:sig
-    foo:msg.a -> println:data
+    foo:msg -> .a -> println:data
     println:sig -> :stop
 }
 
@@ -10,4 +12,4 @@ const s struct { a int } = { a: 42 }
 
 def Foo(sig any) (msg struct{a int}) {
     :sig -> { $s -> :msg }
-}
\ No newline at end of file
+}
diff --git a/e2e/struct_selector_verbose/main/main.neva b/e2e/struct_selector_verbose/main/main.neva
index e02fc49f..c90d0664 100644
--- a/e2e/struct_selector_verbose/main/main.neva
+++ b/e2e/struct_selector_verbose/main/main.neva
@@ -1,3 +1,5 @@
+import { fmt }
+
 // Here we learn how to read struct field
 // by using builtin def with compiler directive.
 
diff --git a/examples/filter_list/e2e_test.go b/examples/filter_list/e2e_test.go
index ed5775f2..b18adc9b 100644
--- a/examples/filter_list/e2e_test.go
+++ b/examples/filter_list/e2e_test.go
@@ -19,7 +19,7 @@ func Test(t *testing.T) {
 	defer os.Chdir(wd)
 
 	for i := 0; i < 1; i++ {
-		cmd := exec.Command("neva", "run", "filter_list")
+		cmd := exec.Command("neva", "run", "-trace", "filter_list")
 
 		// Set a timeout for the command
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
diff --git a/examples/filter_list/main.neva b/examples/filter_list/main.neva
index a0df934e..e69de29b 100644
--- a/examples/filter_list/main.neva
+++ b/examples/filter_list/main.neva
@@ -1,15 +0,0 @@
-import { fmt }
-
-const lst list<int> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-
-def Main(start) (stop) {
-    ListToStream, Filter{Even}, For{fmt.Println}, Wait
-    ---
-    :start -> {
-        $lst -> listToStream -> filter -> for -> wait -> :stop
-    }
-}
-
-def Even(data int) (res bool) {
-    ((:data % 2) == 0) -> :res
-}