[cmake-developers] [CMake 0012458]: cmake_minimum_required clears policies

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://public.kitware.com/Bug/view.php?id=12458 
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Reported By:                Stephen Kelly
Assigned To:                
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Project:                    CMake
Issue ID:                   12458
Category:                   CMake
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
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Date Submitted:             2011-09-14 19:27 EDT
Last Modified:              2011-09-14 19:27 EDT
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Summary:                    cmake_minimum_required clears policies
Description: 
The attached project contains the line 

cmake_policy(SET CMP0017 NEW)

but also warns about the policy not being set:

$ cmake ..
CMake Warning (dev) at /usr/share/cmake-2.8/Modules/FeatureSummary.cmake:112
(INCLUDE):
  File /usr/share/cmake-2.8/Modules/FeatureSummary.cmake includes
  /home/stephen/dev/src/playground/cmakebugs/CMakeParseArguments.cmake (found
  via CMAKE_MODULE_PATH) which shadows
  /usr/share/cmake-2.8/Modules/CMakeParseArguments.cmake.  This may cause
  errors later on .

  Policy CMP0017 is not set: Prefer files from the CMake module directory
  when including from there.  Run "cmake --help-policy CMP0017" for policy
  details.  Use the cmake_policy command to set the policy and suppress this
  warning.
Call Stack (most recent call first):
  sub1/CMakeLists.txt:4 (include)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Configuring done
-- Generating done
-- Build files have been written to:
/home/stephen/dev/src/playground/cmakebugs/build

The warning does not appear if the cmake_minimum_required line in
sub1/CMakeLists.txt is removed. 

The documentation of cmake_minimum_required notes that the policy is implicitly
set to the cmake version specified. However I still found it surprising that it
clears all existing policies.

If this is intentional, it should probably be in the cmake_minimum_required
documentation. 

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Issue History 
Date Modified    Username       Field                    Change               
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2011-09-14 19:27 Stephen Kelly  New Issue                                    
2011-09-14 19:27 Stephen Kelly  File Added: policybug.tar.gz                    
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