CMP0150
-------

.. versionadded:: 3.27

:command:`ExternalProject_Add` and :command:`FetchContent_Declare` commands
treat relative ``GIT_REPOSITORY`` paths as being relative to the parent
project's remote.

Earlier versions of these commands always treated relative paths in
``GIT_REPOSITORY`` as local paths, but the base directory it was treated
as relative to was both undocumented and unintuitive.  The ``OLD`` behavior
for this policy is to interpret relative paths used for ``GIT_REPOSITORY``
as local paths relative to the following:

* The parent directory of ``SOURCE_DIR`` for :command:`ExternalProject_Add`.
* ``FETCHCONTENT_BASE_DIR`` for :command:`FetchContent_Declare`.

The ``NEW`` behavior is to determine the remote from the parent project and
interpret the path relative to that remote.  The value of
:variable:`CMAKE_CURRENT_SOURCE_DIR` when :command:`ExternalProject_Add` or
:command:`FetchContent_Declare` is called determines the parent project.
The remote is selected according to the following (the first match is used):

* If the parent project is checked out on a branch with an upstream remote
  defined, use that remote.
* If only one remote is defined, use that remote.
* If multiple remotes are defined and one of them is named ``origin``, use
  ``origin``'s remote but also issue a warning.

If an appropriate remote cannot be determined from the above, a fatal error
will be raised.

This policy was introduced in CMake version 3.27.  CMake version |release|
warns when a relative path is encountered and the policy is not set,
falling back to using ``OLD`` behavior.  Use the :command:`cmake_policy`
command to set it to ``OLD`` or ``NEW`` explicitly.

.. include:: DEPRECATED.txt
