When building ufs on Hera (with gnu) I see this ccpp (framework and physics) cmake warnings:
CMake Warning (dev) at FV3/ccpp/framework/CMakeLists.txt:15 (find_package):
Policy CMP0074 is not set: find_package uses <PackageName>_ROOT variables.
Run "cmake --help-policy CMP0074" for policy details. Use the cmake_policy
command to set the policy and suppress this warning.
For compatibility, CMake is ignoring the variable.
This warning is for project developers. Use -Wno-dev to suppress it.
> This is the description about CMP0074 policy:
$ cmake --help-policy CMP0074
CMP0074
.. versionadded:: 3.12
find_package() uses <PackageName>_ROOT variables.
In CMake 3.12 and above the find_package(<PackageName>) command now
searches prefixes specified by the <PackageName>_ROOT CMake
variable and the <PackageName>_ROOT environment variable.
Package roots are maintained as a stack so nested calls to all find_*
commands inside find modules and config packages also search the roots as
prefixes. This policy provides compatibility with projects that have not been
updated to avoid using <PackageName>_ROOT variables for other purposes.
The OLD behavior for this policy is to ignore <PackageName>_ROOT
variables. The NEW behavior for this policy is to use
<PackageName>_ROOT variables.
This policy was introduced in CMake version 3.12. CMake version
3.23.1 warns when the policy is not set and uses OLD behavior.
Use the cmake_policy() command to set it to OLD or NEW
explicitly.
.. note::
The OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.
> In both framework and physics the minimum cmake version is set to be 3.10. That means, for compatibility with older cmake versions, `*_ROOT` variables are ignored. To silence this warning we need to either set the policy to `NEW` or update minimum cmake version to `>= 3.12`
## Solution
Current cmake versions used on the tier-1 platforms are somewhere around 3.20 (provided by the operating system or as default modules) or closer to 3.30 (spack-stack built). We can therefore safely increase the minimum version required to 3.18, for example.
## Alternatives (optional)
Do nothing - no good.
## Related to (optional)
https://github.com/NCAR/ccpp-physics/issues/1100
Description
@DusanJovic-NOAA reported this:
Environment variable MPI_ROOT is set to:
/scratch2/NCEPDEV/stmp1/role.epic/installs/openmpi/4.1.6_gnu13.3
For compatibility, CMake is ignoring the variable. This warning is for project developers. Use -Wno-dev to suppress it.
$ cmake --help-policy CMP0074 CMP0074
.. versionadded:: 3.12
find_package()uses<PackageName>_ROOTvariables.In CMake 3.12 and above the
find_package(<PackageName>)command now searches prefixes specified by the<PackageName>_ROOTCMake variable and the<PackageName>_ROOTenvironment variable. Package roots are maintained as a stack so nested calls to allfind_*commands inside find modules and config packages also search the roots as prefixes. This policy provides compatibility with projects that have not been updated to avoid using<PackageName>_ROOTvariables for other purposes.The
OLDbehavior for this policy is to ignore<PackageName>_ROOTvariables. TheNEWbehavior for this policy is to use<PackageName>_ROOTvariables.This policy was introduced in CMake version 3.12. CMake version 3.23.1 warns when the policy is not set and uses
OLDbehavior. Use thecmake_policy()command to set it toOLDorNEWexplicitly... note:: The
OLDbehavior of a policy isdeprecated by definitionand may be removed in a future version of CMake.