CMAKE-ENV-VARIABLES(7)

NAME
cmake-env-variables - CMake Environment Variables Reference

This page lists environment variables that have special meaning to CMake.

For general information on environment variables, see the Environment Variables section in the cmake-language manual.

ENVIRONMENT VARIABLES THAT CHANGE BEHAVIOR

  CLICOLOR

Added in version 3.21.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Set to 0 to tell command-line tools not to print color messages even if connected to a terminal. This is a common convention among command-line tools in general.

See also the NO_COLOR and CLICOLOR_FORCE environment variables. If either of them is activated, it takes precedence over CLICOLOR.

See the CMAKE_COLOR_DIAGNOSTICS variable to control color in a generated build system.

  CLICOLOR_FORCE

Added in version 3.5.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Set to a non-empty value, other than 0, to tell command-line tools to print color messages even if not connected to a terminal. This is a common convention among command-line tools in general.

See also the NO_COLOR and CLICOLOR environment variables. If NO_COLOR is activated, it takes precedence over CLICOLOR_FORCE. Otherwise, if CLICOLOR_FORCE is activated, it takes precedence over CLICOLOR.

See the CMAKE_COLOR_DIAGNOSTICS variable to control color in a generated build system.

  CMAKE_APPBUNDLE_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_APPBUNDLE_PATH environment variable may be set to a list of directories to be searched for macOS application bundles by the find_program() and find_package() commands.

This variable may hold a single directory or a list of directories separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_APPBUNDLE_PATH CMake variable.

  CMAKE_FRAMEWORK_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_FRAMEWORK_PATH environment variable may be set to a list of directories to be searched for macOS frameworks by the find_library(), find_package(), find_path() and find_file() commands.

This variable may hold a single directory or a list of directories separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_FRAMEWORK_PATH CMake variable.

  CMAKE_INCLUDE_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_INCLUDE_PATH environment variable may be set to a list of directories to be searched by the find_file() and find_path() commands.

This variable may hold a single directory or a list of directories separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_INCLUDE_PATH CMake variable.

  CMAKE_LIBRARY_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_LIBRARY_PATH environment variable may be set to a list of directories to be searched by the find_library() command.

This variable may hold a single directory or a list of directories separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_LIBRARY_PATH CMake variable.

  CMAKE_MAXIMUM_RECURSION_DEPTH

Added in version 3.27.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Maximum recursion depth for CMake scripts. This environment variable is used if the CMAKE_MAXIMUM_RECURSION_DEPTH variable is not set. See that variable's documentation for details.

  CMAKE_POLICY_VERSION_MINIMUM

Added in version 4.0.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default value for CMAKE_POLICY_VERSION_MINIMUM when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_POLICY_VERSION_MINIMUM.

  CMAKE_PREFIX_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_PREFIX_PATH environment variable may be set to a list of directories specifying installation prefixes to be searched by the find_package(), find_program(), find_library(), find_file(), and find_path() commands. Each command will add appropriate subdirectories (like bin, lib, or include) as specified in its own documentation.

This variable may hold a single prefix or a list of prefixes separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_PREFIX_PATH CMake variable.

  CMAKE_PROGRAM_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_PROGRAM_PATH environment variable may be set to a list of directories to be searched by the find_program() command.

This variable may hold a single directory or a list of directories separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the CMAKE_PROGRAM_PATH CMake variable.

  CMAKE_TLS_VERIFY

Added in version 3.30.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify the default value for the file(DOWNLOAD) and file(UPLOAD) commands' TLS_VERIFY option. This environment variable is used if the option is not given and the CMAKE_TLS_VERIFY cmake variable is not set.

This variable is also used by the ExternalProject and FetchContent modules for internal calls to file(DOWNLOAD) and git clone.

  CMAKE_TLS_VERSION

Added in version 3.30.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify the default value for the file(DOWNLOAD) and file(UPLOAD) commands' TLS_VERSION option. This environment variable is used if the option is not given and the CMAKE_TLS_VERSION cmake variable is not set. See that variable for allowed values.

This variable is also used by the ExternalProject and FetchContent modules for internal calls to file(DOWNLOAD) and git clone.

  NO_COLOR

Added in version 4.1.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Set to a non-empty value, other than 0, to tell command-line tools not to print color messages even if connected to a terminal. This is a common convention among command-line tools in general.

See also the CLICOLOR_FORCE and CLICOLOR environment variables. If NO_COLOR is activated, it takes precedence over both of them.

See the CMAKE_COLOR_DIAGNOSTICS variable to control color in a generated build system.

  SSL_CERT_DIR

Added in version 3.25.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify default directory containing CA certificates. It overrides the default CA directory used.

  SSL_CERT_FILE

Added in version 3.25.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify the file name containing CA certificates. It overrides the default, os-specific CA file used.

ENVIRONMENT VARIABLES THAT CONTROL THE BUILD

  ADSP_ROOT

Added in version 3.24.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The ADSP_ROOT environment variable specifies a default value for the CMAKE_ADSP_ROOT variable when there is no explicit configuration given on the first run while creating a new build tree.

  CMAKE_APPLE_SILICON_PROCESSOR

Added in version 3.19.2.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

On Apple Silicon hosts running macOS, set this environment variable to tell CMake what architecture to use for CMAKE_HOST_SYSTEM_PROCESSOR. The value must be either arm64 or x86_64.

The CMAKE_APPLE_SILICON_PROCESSOR normal variable, if set, overrides this environment variable.

  CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY

Added in version 4.2.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY is a string specifying the strategy to use for autogen-related target intermediate directories. It initializes the CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY variable.

  CMAKE_BUILD_PARALLEL_LEVEL

Added in version 3.12.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specifies the maximum number of concurrent processes to use when building using the cmake --build command line Build Tool Mode. For example, if CMAKE_BUILD_PARALLEL_LEVEL is set to 8, the underlying build tool will execute up to 8 jobs concurrently as if cmake --build were invoked with the --parallel 8 option.

If this variable is defined empty the native build tool's default number is used.

  CMAKE_BUILD_TYPE

Added in version 3.22.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_BUILD_TYPE environment variable specifies a default value for the CMAKE_BUILD_TYPE variable when there is no explicit configuration given on the first run while creating a new build tree.

  CMAKE_COLOR_DIAGNOSTICS

Added in version 3.24.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specifies a default value for the CMAKE_COLOR_DIAGNOSTICS variable when there is no explicit value given on the first run.

  CMAKE_CONFIG_DIR

Added in version 3.31.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify a CMake user-wide configuration directory for cmake-file-api(7) queries.

If this environment variable is not set, the default user-wide configuration directory is platform-specific:

•   Windows: %LOCALAPPDATA%\CMake

•   macOS: $XDG_CONFIG_HOME/CMake if set, otherwise $HOME/Library/Application Support/CMake

•   Linux/Other: $XDG_CONFIG_HOME/cmake if set, otherwise $HOME/.config/cmake

  CMAKE_CONFIG_TYPE

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default build configuration for Build a Project and ctest build handler when there is no explicit configuration given.

  CMAKE_CONFIGURATION_TYPES

Added in version 3.22.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_CONFIGURATION_TYPES environment variable specifies a default value for the CMAKE_CONFIGURATION_TYPES variable when there is no explicit configuration given on the first run while creating a new build tree.

  CMAKE_CROSSCOMPILING_EMULATOR

Added in version 3.28.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default value for CMAKE_CROSSCOMPILING_EMULATOR when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_CROSSCOMPILING_EMULATOR.

  CMAKE_EXPORT_BUILD_DATABASE

Added in version 3.31.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default value for CMAKE_EXPORT_BUILD_DATABASE when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_EXPORT_BUILD_DATABASE.

NOTE: This variable is meaningful only when experimental support for build databases has been enabled by the CMAKE_EXPERIMENTAL_EXPORT_BUILD_DATABASE gate.

  CMAKE_EXPORT_COMPILE_COMMANDS

Added in version 3.17.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default value for CMAKE_EXPORT_COMPILE_COMMANDS when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_EXPORT_COMPILE_COMMANDS.

  CMAKE_FASTBUILD_VERBOSE_GENERATOR

Added in version 4.2.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_FASTBUILD_VERBOSE_GENERATOR environment variable specifies a custom default value for the CMAKE_FASTBUILD_VERBOSE_GENERATOR variable in place of the default values specified by CMake itself.

  CMAKE_GENERATOR

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specifies the CMake default generator to use when no generator is supplied with -G. If the provided value doesn't name a generator known by CMake, the internal default is used. Either way the resulting generator selection is stored in the CMAKE_GENERATOR variable.

Some generators may be additionally configured using the environment variables:

•   CMAKE_GENERATOR_PLATFORM

•   CMAKE_GENERATOR_TOOLSET

•   CMAKE_GENERATOR_INSTANCE

  CMAKE_GENERATOR_INSTANCE

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Default value for CMAKE_GENERATOR_INSTANCE if no Cache entry is present. This value is only applied if CMAKE_GENERATOR is set.

  CMAKE_GENERATOR_PLATFORM

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Default value for CMAKE_GENERATOR_PLATFORM if no Cache entry is present and no value is specified by cmake -A option. This value is only applied if CMAKE_GENERATOR is set.

  CMAKE_GENERATOR_TOOLSET

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Default value for CMAKE_GENERATOR_TOOLSET if no Cache entry is present and no value is specified by cmake -T option. This value is only applied if CMAKE_GENERATOR is set.

  CMAKE_INSTALL_MODE

Added in version 3.22.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_INSTALL_MODE environment variable allows users to operate CMake in an alternate mode of file(INSTALL) and install().

The default behavior for an installation is to copy a source file from a source directory into a destination directory. This environment variable however allows the user to override this behavior, causing CMake to create symbolic links instead.

  Usage Scenarios

Installing symbolic links rather than copying files can help in the following ways:

•   Conserving storage space because files do not have to be duplicated on disk.

•   Changes to the source of the symbolic link are seen at the install destination without having to re-run the install step.

•   Editing through the link at the install destination will modify the source of the link. This may be useful when dealing with CMake project hierarchies, i.e. using ExternalProject and consistent source navigation and refactoring is desired across projects.

  Allowed Values

The following values are allowed for CMAKE_INSTALL_MODE:

COPY, empty or unset
    Duplicate the file at its destination. This is the default behavior.

ABS_SYMLINK
    Create an absolute symbolic link to the source file at the destination. Halt with an error if the link cannot be created.

ABS_SYMLINK_OR_COPY
    Like ABS_SYMLINK but fall back to silently copying if the symlink couldn't be created.

REL_SYMLINK
    Create a relative symbolic link to the source file at the destination. Halt with an error if the link cannot be created.

REL_SYMLINK_OR_COPY
    Like REL_SYMLINK but fall back to silently copying if the symlink couldn't be created.

SYMLINK
    Try as if through REL_SYMLINK and fall back to ABS_SYMLINK if the referenced file cannot be expressed using a relative path. Halt with an error if the link cannot be created.

SYMLINK_OR_COPY
    Like SYMLINK but fall back to silently copying if the symlink couldn't be created.

    NOTE: A symbolic link consists of a reference file path rather than contents of its own, hence there are two ways to express the relation, either by a relative or an absolute path.

  When To Set The Environment Variable

For the environment variable to take effect, it must be set during the correct build phase(s).

•   If the project calls file(INSTALL) directly, the environment variable must be set during the configuration phase.

•   In order to apply to install(), the environment variable must be set during installation. This could be during a build if using the install or package build targets, or separate from the build when invoking an install or running cpack from the command line.

•   When using ExternalProject, it might be required during the build phase, since the external project's own configure, build and install steps will execute during the main project's build phase.

    Given the above, it is recommended to set the environment variable consistently across all phases (configure, build and install).

  Caveats

Use this environment variable with caution. The following highlights some points to be considered:

•   CMAKE_INSTALL_MODE only affects files, not directories.

•   Symbolic links are not available on all platforms.

•   The way this environment variable interacts with the install step of ExternalProject is more complex. For further details, see that module's documentation.

•   A symbolic link ties the destination to the source in a persistent way. Writing to either of the two affects both file system objects. This is in contrast to normal install behavior which only copies files as they were at the time the install was performed, with no enduring relationship between the source and destination of the install.

•   Combining CMAKE_INSTALL_MODE with IOS_INSTALL_COMBINED is not supported.

•   Changing CMAKE_INSTALL_MODE from what it was on a previous run can lead to unexpected results. Moving from a non-symlinking mode to a symlinking mode will discard any previous file at the destination, but the reverse is not true. Once a symlink exists at the destination, even if you switch to a non-symlink mode, the symlink will continue to exist at the destination and will not be replaced by an actual file.

  CMAKE_INSTALL_PARALLEL_LEVEL

Added in version 3.31.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specifies the default maximum number of concurrent processes to use when installing using cmake --install.

This has no impact unless INSTALL_PARALLEL is enabled.

  CMAKE_INSTALL_PREFIX

Added in version 3.29.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_INSTALL_PREFIX environment variable specifies a custom default value for the CMAKE_INSTALL_PREFIX variable in place of the default values specified by CMake itself. The value specified must be an absolute path to a directory.

  CMAKE_INTERMEDIATE_DIR_STRATEGY

Added in version 4.2.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

CMAKE_INTERMEDIATE_DIR_STRATEGY is a string specifying the strategy to use for target intermediate directories. It initializes the CMAKE_INTERMEDIATE_DIR_STRATEGY variable.

  CMAKE_<LANG>_COMPILER_LAUNCHER

Added in version 3.17.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Default compiler launcher to use for the specified language. Will only be used by CMake to initialize the variable on the first configuration. Afterwards, it is available through the cache setting of the variable of the same name. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_<LANG>_COMPILER_LAUNCHER variable is defined.

  CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES_EXCLUDE

Added in version 3.27.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

A semicolon-separated list of directories to exclude from the CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES variable when it is automatically detected from the <LANG> compiler.

This may be used to work around misconfigured compiler drivers that pass extraneous implicit link directories to their linker.

See also the CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE environment variable.

  CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE

Added in version 4.1.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

A semicolon-separated list of libraries to exclude from the CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES variable when it is automatically detected from the <LANG> compiler.

This may be used to work around detection limitations that result in extraneous implicit link libraries, e.g., when using compiler driver flags that affect the set of implicitly linked libraries.

See also the CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES_EXCLUDE environment variable.

  CMAKE_<LANG>_LINKER_LAUNCHER

Added in version 3.21.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Default launcher to use when linking a target of the specified language. Will only be used by CMake to initialize the variable on the first configuration. Afterwards, it is available through the cache setting of the variable of the same name. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_<LANG>_LINKER_LAUNCHER variable is defined.

  CMAKE_MSVCIDE_RUN_PATH

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Extra PATH locations for custom commands when using Visual Studio Generators.

The CMAKE_MSVCIDE_RUN_PATH environment variable sets the default value for the CMAKE_MSVCIDE_RUN_PATH variable if not already explicitly set.

  CMAKE_NO_VERBOSE

Added in version 3.14.

Disables verbose output from CMake when VERBOSE environment variable is set.

Only your build tool of choice will still print verbose output when you start to actually build your project.

  CMAKE_OSX_ARCHITECTURES

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Target specific architectures for macOS.

The CMAKE_OSX_ARCHITECTURES environment variable sets the default value for the CMAKE_OSX_ARCHITECTURES variable. See OSX_ARCHITECTURES for more information.

  CMAKE_TEST_LAUNCHER

Added in version 3.29.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The default value for the CMAKE_TEST_LAUNCHER variable when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_TEST_LAUNCHER.

  CMAKE_TOOLCHAIN_FILE

Added in version 3.21.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

The CMAKE_TOOLCHAIN_FILE environment variable specifies a default value for the CMAKE_TOOLCHAIN_FILE variable when there is no explicit configuration given on the first run while creating a new build tree. On later runs in an existing build tree the value persists in the cache as CMAKE_TOOLCHAIN_FILE.

  DESTDIR

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

On UNIX one can use the DESTDIR mechanism in order to relocate the whole installation. DESTDIR means DESTination DIRectory. It is commonly used by packagers to install software in a staging directory.

For example, running

    make DESTDIR=/package/stage install

will install the software using the installation prefix, e.g. /usr/local, prepended with the DESTDIR value which gives /package/stage/usr/local. The packaging tool may then construct the package from the content of the /package/stage directory.

See the CMAKE_INSTALL_PREFIX variable to control the installation prefix when configuring a build tree. Or, when using the cmake(1) command-line tool's --install mode, one may specify a different prefix using the --prefix option.

NOTE: DESTDIR may not be used on Windows because installation prefix usually contains a drive letter like in C:/Program Files which cannot be prepended with some other prefix.

  LDFLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Will only be used by CMake on the first configuration to determine the default linker flags, after which the value for LDFLAGS is stored in the cache as CMAKE_EXE_LINKER_FLAGS_INIT, CMAKE_SHARED_LINKER_FLAGS_INIT, and CMAKE_MODULE_LINKER_FLAGS_INIT. For any configuration run (including the first), the environment variable will be ignored if the equivalent CMAKE_<TYPE>_LINKER_FLAGS_INIT variable is defined.

  MACOSX_DEPLOYMENT_TARGET

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify the minimum version of macOS on which the target binaries are to be deployed.

The MACOSX_DEPLOYMENT_TARGET environment variable sets the default value for the CMAKE_OSX_DEPLOYMENT_TARGET variable.

  <PackageName>_ROOT

Added in version 3.12.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Calls to find_package(<PackageName>) will search in prefixes specified by the <PackageName>_ROOT environment variable, where <PackageName> is the (case-preserved) name given to the find_package() call and _ROOT is literal. For example, find_package(Foo) will search prefixes specified in the Foo_ROOT environment variable (if set). See policy CMP0074.

This variable may hold a single prefix or a list of prefixes separated by : on UNIX or ; on Windows (the same as the PATH environment variable convention on those platforms).

See also the <PackageName>_ROOT CMake variable.

<PACKAGENAME>_ROOT
    Added in version 3.27.

    Calls to find_package(<PackageName>) will also search in prefixes specified by the upper-case <PACKAGENAME>_ROOT environment variable. See policy CMP0144.

    NOTE: Note that the <PackageName>_ROOT and <PACKAGENAME>_ROOT environment variables are distinct only on platforms that have case-sensitive environments.

  VERBOSE

Added in version 3.14.

Activates verbose output from CMake and your build tools of choice when you start to actually build your project.

Note that any given value is ignored. It's just checked for existence.

See also Build Tool Mode and CMAKE_NO_VERBOSE environment variable

ENVIRONMENT VARIABLES FOR LANGUAGES

  ASM<DIALECT>

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling a specific dialect of assembly language files. ASM<DIALECT> can be one of:

•   ASM

•   ASM_NASM (Netwide Assembler)

•   ASM_MASM (Microsoft Assembler)

•   ASM_MARMASM (Microsoft ARM Assembler)

•   ASM-ATT (Assembler AT&T)

    Will only be used by CMake on the first configuration to determine ASM<DIALECT> compiler, after which the value for ASM<DIALECT> is stored in the cache as CMAKE_ASM<DIALECT>_COMPILER. For subsequent configuration runs, the environment variable will be ignored in favor of CMAKE_ASM<DIALECT>_COMPILER.

    NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

        $ export ASM="custom-compiler --arg1 --arg2"

  ASM<DIALECT>FLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling a specific dialect of an assembly language. ASM<DIALECT>FLAGS can be one of:

•   ASMFLAGS

•   ASM_NASMFLAGS

•   ASM_MASMFLAGS

•   ASM_MARMASMFLAGS

•   ASM-ATTFLAGS

    CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_ASM<DIALECT>_FLAGS cache entry. This occurs the first time a build tree is configured for language ASM<DIALECT>. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_ASM<DIALECT>_FLAGS variable is already defined.

    See also CMAKE_ASM<DIALECT>_FLAGS_INIT.

  CC

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling C language files. Will only be used by CMake on the first configuration to determine C compiler, after which the value for CC is stored in the cache as CMAKE_C_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_C_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export CC="custom-compiler --arg1 --arg2"

  CFLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling C files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_C_FLAGS cache entry. This occurs the first time a build tree is configured for language C. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_C_FLAGS variable is already defined.

See also CMAKE_C_FLAGS_INIT.

  CSFLAGS

Added in version 3.9.2.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling CSharp files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_CSharp_FLAGS cache entry. This occurs the first time a build tree is configured for language CSharp. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_CSharp_FLAGS variable is already defined.

See also CMAKE_CSharp_FLAGS_INIT.

  CUDAARCHS

Added in version 3.20.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Value used to initialize CMAKE_CUDA_ARCHITECTURES on the first configuration. Subsequent runs will use the value stored in the cache.

This is a semicolon-separated list of architectures as described in CUDA_ARCHITECTURES.

  CUDACXX

Added in version 3.8.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling CUDA language files. Will only be used by CMake on the first configuration to determine CUDA compiler, after which the value for CUDA is stored in the cache as CMAKE_CUDA_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_CUDA_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export CUDACXX="custom-compiler --arg1 --arg2"

  CUDAFLAGS

Added in version 3.8.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling CUDA files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_CUDA_FLAGS cache entry. This occurs the first time a build tree is configured for language CUDA. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_CUDA_FLAGS variable is already defined.

See also CMAKE_CUDA_FLAGS_INIT.

  CUDAHOSTCXX

Added in version 3.8.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling host code when compiling CUDA language files. Will only be used by CMake on the first configuration to determine CUDA host compiler, after which the value for CUDAHOSTCXX is stored in the cache as CMAKE_CUDA_HOST_COMPILER. This environment variable is preferred over CMAKE_CUDA_HOST_COMPILER.

This environment variable is primarily meant for use with projects that enable CUDA as a first-class language.

NOTE: Ignored when using Visual Studio Generators.

Added in version 3.13: The FindCUDA module will use this variable to initialize its CUDA_HOST_COMPILER setting.

  CXX

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling CXX language files. Will only be used by CMake on the first configuration to determine CXX compiler, after which the value for CXX is stored in the cache as CMAKE_CXX_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_CXX_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export CXX="custom-compiler --arg1 --arg2"

  CXXFLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling CXX (C++) files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_CXX_FLAGS cache entry. This occurs the first time a build tree is configured for language CXX. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_CXX_FLAGS variable is already defined.

See also CMAKE_CXX_FLAGS_INIT.

  FC

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling Fortran language files. Will only be used by CMake on the first configuration to determine Fortran compiler, after which the value for Fortran is stored in the cache as CMAKE_Fortran_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_Fortran_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export FC="custom-compiler --arg1 --arg2"

  FFLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling Fortran files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_Fortran_FLAGS cache entry. This occurs the first time a build tree is configured for language Fortran. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_Fortran_FLAGS variable is already defined.

See also CMAKE_Fortran_FLAGS_INIT.

  HIPCXX

Added in version 3.21.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling HIP language files. Will only be used by CMake on the first configuration to determine HIP compiler, after which the value for HIP is stored in the cache as CMAKE_HIP_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_HIP_COMPILER variable is defined.

  HIPFLAGS

Added in version 3.21.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling HIP files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_HIP_FLAGS cache entry. This occurs the first time a build tree is configured for language HIP. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_HIP_FLAGS variable is already defined.

See also CMAKE_HIP_FLAGS_INIT.

  HIPHOSTCXX

Added in version 3.28.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling host code when compiling HIP language files with the NVIDIA CUDA Compiler. Will only be used by CMake on the first configuration to determine HIP host compiler, after which the value for HIPHOSTCXX is stored in the cache as CMAKE_HIP_HOST_COMPILER.

This environment variable is primarily meant for use with projects that enable HIP as a first-class language.

NOTE: Ignored when using Visual Studio Generators.

  ISPC

Added in version 3.19.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling ISPC language files. Will only be used by CMake on the first configuration to determine ISPC compiler, after which the value for ISPC is stored in the cache as CMAKE_ISPC_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_ISPC_COMPILER variable is defined.

  ISPCFLAGS

Added in version 3.19.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling ISPC files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_ISPC_FLAGS cache entry. This occurs the first time a build tree is configured for language ISPC. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_ISPC_FLAGS variable is already defined.

See also CMAKE_ISPC_FLAGS_INIT.

  OBJC

Added in version 3.16.7.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling OBJC language files. Will only be used by CMake on the first configuration to determine OBJC compiler, after which the value for OBJC is stored in the cache as CMAKE_OBJC_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_OBJC_COMPILER variable is defined.

If OBJC is not defined, the CC environment variable will be checked instead.

  OBJCFLAGS

Added in version 3.16.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling Objective C files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_OBJC_FLAGS cache entry. This occurs the first time a build tree is configured for language OBJC. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_OBJC_FLAGS variable is already defined.

See also CMAKE_OBJC_FLAGS_INIT.

  OBJCXX

Added in version 3.16.7.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling OBJCXX language files. Will only be used by CMake on the first configuration to determine OBJCXX compiler, after which the value for OBJCXX is stored in the cache as CMAKE_OBJCXX_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_OBJCXX_COMPILER variable is defined.

If OBJCXX is not defined, the CXX environment variable will be checked instead.

  OBJCXXFLAGS

Added in version 3.16.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling Objective C++ (.mm) files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_OBJCXX_FLAGS cache entry. This occurs the first time a build tree is configured for language OBJCXX. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_OBJCXX_FLAGS variable is already defined.

See also CMAKE_OBJCXX_FLAGS_INIT.

  RC

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling resource files. Will only be used by CMake on the first configuration to determine resource compiler, after which the value for RC is stored in the cache as CMAKE_RC_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_RC_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export RC="custom-compiler --arg1 --arg2"

  RCFLAGS

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Add default compilation flags to be used when compiling RC (resource) files.

CMake uses this environment variable value, in combination with its own builtin default flags for the toolchain, to initialize and store the CMAKE_RC_FLAGS cache entry. This occurs the first time a build tree is configured for language RC. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_RC_FLAGS variable is already defined.

See also CMAKE_RC_FLAGS_INIT.

  SWIFTC

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling Swift language files. Will only be used by CMake on the first configuration to determine Swift compiler, after which the value for SWIFTC is stored in the cache as CMAKE_Swift_COMPILER. For any configuration run (including the first), the environment variable will be ignored if the CMAKE_Swift_COMPILER variable is defined.

NOTE: Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export SWIFTC="custom-compiler --arg1 --arg2"

ENVIRONMENT VARIABLES FOR CTEST

  CTEST_INTERACTIVE_DEBUG_MODE

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Environment variable that will exist and be set to 1 when a test executed by ctest(1) is run in interactive mode.

  CTEST_NO_TESTS_ACTION

Added in version 3.26.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Environment variable that controls how ctest handles cases when there are no tests to run. Possible values are: error, ignore, empty or unset.

The --no-tests=<action> option to ctest overrides this environment variable if both are given.

  CTEST_OUTPUT_ON_FAILURE

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Boolean environment variable that controls if the output should be logged for failed tests. Set the value to 1, True, or ON to enable output on failure. See ctest(1) for more information on controlling output of failed tests.

  CTEST_PARALLEL_LEVEL

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specify the number of tests for CTest to run in parallel. For example, if CTEST_PARALLEL_LEVEL is set to 8, CTest will run up to 8 tests concurrently as if ctest were invoked with the --parallel 8 option.

Changed in version 3.29: The value may be empty, or 0, to let ctest use a default level of parallelism, or unbounded parallelism, respectively, as documented by the ctest --parallel option.

CTest will interpret a whitespace-only string as empty.

In CMake 3.28 and earlier, an empty or 0 value was equivalent to 1.

See ctest(1) for more information on parallel test execution.

  CTEST_PROGRESS_OUTPUT

Added in version 3.13.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Boolean environment variable that affects how ctest command output reports overall progress. When set to 1, TRUE, ON or anything else that evaluates to boolean true, progress is reported by repeatedly updating the same line. This greatly reduces the overall verbosity, but is only supported when output is sent directly to a terminal. If the environment variable is not set or has a value that evaluates to false, output is reported normally with each test having its own start and end lines logged to the output.

The --progress option to ctest overrides this environment variable if both are given.

  CTEST_USE_INSTRUMENTATION

Added in version 4.0.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

NOTE: This feature is only available when experimental support for instrumentation has been enabled by the CMAKE_EXPERIMENTAL_INSTRUMENTATION gate.

Setting this environment variable to 1, True, or ON enables instrumentation for CTest in Dashboard Client mode.

  CTEST_USE_LAUNCHERS_DEFAULT

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Initializes the CTEST_USE_LAUNCHERS variable if not already defined.

  CTEST_USE_VERBOSE_INSTRUMENTATION

Added in version 4.0.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

NOTE: This feature is only available when experimental support for instrumentation has been enabled by the CMAKE_EXPERIMENTAL_INSTRUMENTATION gate.

Setting this environment variable to 1, True, or ON causes CTest to report the full command line (including arguments) to CDash for each instrumented command. By default, CTest truncates the command line at the first space.

See also CTEST_USE_INSTRUMENTATION

  DASHBOARD_TEST_FROM_CTEST

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Environment variable that will exist when a test executed by ctest(1) is run in non-interactive mode. The value will be equal to CMAKE_VERSION.

ENVIRONMENT VARIABLES FOR THE CMAKE CURSES INTERFACE

  CCMAKE_COLORS

Added in version 3.18.

Determines what colors are used by the CMake curses interface, when run on a terminal that supports colors. The syntax follows the same conventions as LS_COLORS; that is, a list of key/value pairs separated by :.

Keys are a single letter corresponding to a CMake cache variable type:

•   s: A STRING.

•   p: A FILEPATH.

•   c: A value which has an associated list of choices.

•   y: A BOOL which has a true-like value (e.g. ON, YES).

•   n: A BOOL which has a false-like value (e.g. OFF, NO).

    Values are an integer number that specifies what color to use. 0 is black (you probably don't want to use that). Others are determined by your terminal's color support. Most (color) terminals will support at least 8 or 16 colors. Some will support up to 256 colors. The colors will likely match this chart, although the first 16 colors may match the original CGA color palette. (Many modern terminal emulators also allow their color palette, at least for the first 16 colors, to be configured by the user.)

    Note that fairly minimal checking is done for bad colors (although a value higher than what curses believes your terminal supports will be silently ignored) or bad syntax.

    For example:

        CCMAKE_COLORS='s=39:p=220:c=207:n=196:y=46'

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