doc: document empty alias

Alizter · Alizter · commit 94c8024e8046 · 2025-07-02T17:09:30.000+02:00
Signed-off-by: Ali Caglayan &lt;alizter@gmail.com&gt;
diff --git a/doc/changes/11956.md b/doc/changes/11956.md
@@ -0,0 +1,2 @@
+- Added 'empty' alias which contains no targets. (#11556 #11952 #11955 #11956,
+  grants #4161, @Alizter and @rgrinberg)
diff --git a/doc/reference/aliases.rst b/doc/reference/aliases.rst
@@ -70,6 +70,7 @@ Some aliases are defined and managed by Dune itself:
        aliases/default
        aliases/install
        aliases/pkg-install
+       aliases/empty
 
   .. grid-item::
 
diff --git a/doc/reference/aliases/empty.rst b/doc/reference/aliases/empty.rst
@@ -0,0 +1,9 @@
+@empty
+======
+
+The `empty` alias contains no targets.
+
+As of Dune language version 3.20, user-defined :doc:`rule <../dune/rule>` and
+:doc:`alias <../dune/alias>` stanzas are no longer permitted to extend the
+`empty` alias.
+

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+- Added 'empty' alias which contains no targets. (#11556 #11952 #11955 #11956,`
	`2`	`+ grants #4161, @Alizter and @rgrinberg)`