EXPORT_PACKAGE_DEPENDENCIES: Add experimental feature gate

Some design concerns have been raised after trying the 3.29 release
candidates.  Avoid committing to a stable public interface for now.

Issue: #25767

1 files changed, 25 insertions, 0 deletions

diff --git a/Help/dev/experimental.rst b/Help/dev/experimental.rst
index 87ac031..fc4ac8b 100644
--- a/Help/dev/experimental.rst
+++ b/Help/dev/experimental.rst
@@ -13,3 +13,28 @@ specific values will change over time to reinforce their experimental nature.
 When used, a warning will be generated to indicate that an experimental
 feature is in use and that the affected behavior in the project is not part of
 CMake's stability guarantees.
+
+Export Package Dependencies
+===========================
+
+In order to activate support for this experimental feature, set
+
+* variable ``CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES`` to
+* value ``1942b4fa-b2c5-4546-9385-83f254070067``.
+
+This UUID may change in future versions of CMake.  Be sure to use the value
+documented here by the source tree of the version of CMake with which you are
+experimenting.
+
+When activated, this experimental feature provides the following:
+
+* The ``install(EXPORT)`` and ``export(EXPORT)`` commands have experimental
+  ``EXPORT_PACKAGE_DEPENDENCIES`` arguments to generate ``find_dependency``
+  calls automatically.
+
+* Details of the calls may be configured using the ``export(SETUP)``
+  command's ``PACKAGE_DEPENDENCY`` argument.
+
+* The package name associated with specific targets may be specified
+  using the ``CMAKE_EXPORT_FIND_PACKAGE_NAME`` variable and/or
+``EXPORT_FIND_PACKAGE_NAME`` target property.