Remove !include error

src/compile_error.rs

@@ -229,10 +229,6 @@ impl Display for CompileError<'_> {
         f,
         "the guard `?` and infallible `-` sigils may not be used together"
       ),
-      Include => write!(
-        f,
-        "the `!include` directive has been stabilized as `import`"
-      ),
       IncompatibleSettings {
         first,
         first_line,

src/compile_error_kind.rs

@@ -119,7 +119,6 @@ pub(crate) enum CompileErrorKind<'src> {
     function: &'src str,
   },
   GuardAndInfallibleSigil,
-  Include,
   IncompatibleSettings {
     first: Keyword,
     first_line: usize,

src/lexer.rs

@@ -474,7 +474,6 @@ impl<'src> Lexer<'src> {
   fn lex_normal(&mut self, start: char) -> CompileResult<'src> {
     match start {
       ' ' | '\t' => self.lex_whitespace(),
-      '!' if self.rest().starts_with("!include") => Err(self.error(Include)),
       '!' => self.lex_choices('!', &[('=', BangEquals), ('~', BangTilde)], Bang),
       '#' => self.lex_comment(),
       '$' => self.lex_single(Dollar),

tests/imports.rs

@@ -156,22 +156,6 @@ fn listed_recipes_in_imports_are_in_load_order() {
     .success();
 }
 
-#[test]
-fn include_error() {
-  Test::new()
-    .justfile("!include foo")
-    .stderr(
-      "
-        error: the `!include` directive has been stabilized as `import`
-         ——▶ justfile:1:1
-          │
-        1 │ !include foo
-          │ ^
-      ",
-    )
-    .failure();
-}
-
 #[test]
 fn recipes_in_import_are_overridden_by_recipes_in_parent() {
   Test::new()

tests/negation.rs

@@ -34,3 +34,21 @@ fn requires_lists_setting() {
     )
     .failure();
 }
+
+#[test]
+fn negate_include() {
+  Test::new()
+    .justfile(
+      "
+        set unstable
+        set lists
+
+        include := []
+
+        x := !include
+      ",
+    )
+    .args(["--evaluate", "x"])
+    .stdout("true")
+    .success();
+}