1CMP0013
2-------
3
4Duplicate binary directories are not allowed.
5
6CMake 2.6.3 and below silently permitted add_subdirectory() calls to
7create the same binary directory multiple times.  During build system
8generation files would be written and then overwritten in the build
9tree and could lead to strange behavior.  CMake 2.6.4 and above
10explicitly detect duplicate binary directories.  CMake 2.6.4 always
11considers this case an error.  In CMake 2.8.0 and above this policy
12determines whether or not the case is an error.  The ``OLD`` behavior for
13this policy is to allow duplicate binary directories.  The NEW
14behavior for this policy is to disallow duplicate binary directories
15with an error.
16
17This policy was introduced in CMake version 2.8.0.  CMake version
18|release| warns when the policy is not set and uses ``OLD`` behavior.  Use
19the :command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
20
21.. include:: DEPRECATED.txt
22