find_package

Note

The Using Dependencies Guide provides a high-level introduction to this general topic. It provides a broader overview of where the find_package() command fits into the bigger picture, including its relationship to the FetchContent module. The guide is recommended pre-reading before moving on to the details below.

Find a package (usually provided by something external to the project), and load its package-specific details. Calls to this command can also be intercepted by dependency providers.

Search Modes

The command has a few modes by which it searches for packages:

Module mode

In this mode, CMake searches for a file called Find<PackageName>.cmake, looking first in the locations listed in the CMAKE_MODULE_PATH, then among the Find Modules provided by the CMake installation. If the file is found, it is read and processed by CMake. It is responsible for finding the package, checking the version, and producing any needed messages. Some Find modules provide limited or no support for versioning; check the Find module's documentation.

The Find<PackageName>.cmake file is not typically provided by the package itself. Rather, it is normally provided by something external to the package, such as the operating system, CMake itself, or even the project from which the find_package() command was called. Being externally provided, Find Modules tend to be heuristic in nature and are susceptible to becoming out-of-date. They typically search for certain libraries, files and other package artifacts.

Module mode is only supported by the basic command signature.

Config mode

In this mode, CMake searches for a file called <lowercasePackageName>-config.cmake or <PackageName>Config.cmake. It will also look for <lowercasePackageName>-config-version.cmake or <PackageName>ConfigVersion.cmake if version details were specified (see Config Mode Version Selection for an explanation of how these separate version files are used).

In config mode, the command can be given a list of names to search for as package names. The locations where CMake searches for the config and version files is considerably more complicated than for Module mode (see Config Mode Search Procedure).

The config and version files are typically installed as part of the package, so they tend to be more reliable than Find modules. They usually contain direct knowledge of the package contents, so no searching or heuristics are needed within the config or version files themselves.

Config mode is supported by both the basic and full command signatures.

FetchContent redirection mode

New in version 3.24: A call to find_package() can be redirected internally to a package provided by the FetchContent module. To the caller, the behavior will appear similar to Config mode, except that the search logic is by-passed and the component information is not used. See FetchContent_Declare() and FetchContent_MakeAvailable() for further details.

When not redirected to a package provided by FetchContent, the command arguments determine whether Module or Config mode is used. When the basic signature is used, the command searches in Module mode first. If the package is not found, the search falls back to Config mode. A user may set the CMAKE_FIND_PACKAGE_PREFER_CONFIG variable to true to reverse the priority and direct CMake to search using Config mode first before falling back to Module mode. The basic signature can also be forced to use only Module mode with a MODULE keyword. If the full signature is used, the command only searches in Config mode.

Where possible, user code should generally look for packages using the basic signature, since that allows the package to be found with any mode. Project maintainers wishing to provide a config package should understand the bigger picture, as explained in Full Signature and all subsequent sections on this page.

Basic Signature

find_package(<PackageName> [version] [EXACT] [QUIET] [MODULE]
             [REQUIRED] [[COMPONENTS] [components...]]
             [OPTIONAL_COMPONENTS components...]
             [REGISTRY_VIEW  (64|32|64_32|32_64|HOST|TARGET|BOTH)]
             [GLOBAL]
             [NO_POLICY_SCOPE]
             [BYPASS_PROVIDER])

The basic signature is supported by both Module and Config modes. The MODULE keyword implies that only Module mode can be used to find the package, with no fallback to Config mode.

Regardless of the mode used, a <PackageName>_FOUND variable will be set to indicate whether the package was found. When the package is found, package-specific information may be provided through other variables and Imported Targets documented by the package itself. The QUIET option disables informational messages, including those indicating that the package cannot be found if it is not REQUIRED. The REQUIRED option stops processing with an error message if the package cannot be found.

A package-specific list of required components may be listed after the COMPONENTS keyword. If any of these components are not able to be satisfied, the package overall is considered to be not found. If the REQUIRED option is also present, this is treated as a fatal error, otherwise execution still continues. As a form of shorthand, if the REQUIRED option is present, the COMPONENTS keyword can be omitted and the required components can be listed directly after REQUIRED.

Additional optional components may be listed after OPTIONAL_COMPONENTS. If these cannot be satisfied, the package overall can still be considered found, as long as all required components are satisfied.

The set of available components and their meaning are defined by the target package. Formally, it is up to the target package how to interpret the component information given to it, but it should follow the expectations stated above. For calls where no components are specified, there is no single expected behavior and target packages should clearly define what occurs in such cases. Common arrangements include assuming it should find all components, no components or some well-defined subset of the available components.

New in version 3.24: The REGISTRY_VIEW keyword specifies which registry views should be queried. This keyword is only meaningful on Windows platforms and will be ignored on all others. Formally, it is up to the target package how to interpret the registry view information given to it.

New in version 3.24: Specifying the GLOBAL keyword will promote all imported targets to a global scope in the importing project. Alternatively, this functionality can be enabled by setting the CMAKE_FIND_PACKAGE_TARGETS_GLOBAL variable.

The [version] argument requests a version with which the package found should be compatible. There are two possible forms in which it may be specified:

• A single version with the format major[.minor[.patch[.tweak]]], where each component is a numeric value.

• A version range with the format versionMin...[<]versionMax where versionMin and versionMax have the same format and constraints on components being integers as the single version. By default, both end points are included. By specifying <, the upper end point will be excluded. Version ranges are only supported with CMake 3.19 or later.

The EXACT option requests that the version be matched exactly. This option is incompatible with the specification of a version range.

If no [version] and/or component list is given to a recursive invocation inside a find-module, the corresponding arguments are forwarded automatically from the outer call (including the EXACT flag for [version]). Version support is currently provided only on a package-by-package basis (see the Version Selection section below). When a version range is specified but the package is only designed to expect a single version, the package will ignore the upper end point of the range and only take the single version at the lower end of the range into account.

See the cmake_policy() command documentation for discussion of the NO_POLICY_SCOPE option.

New in version 3.24: The BYPASS_PROVIDER keyword is only allowed when find_package() is being called by a dependency provider. It can be used by providers to call the built-in find_package() implementation directly and prevent that call from being re-routed back to itself. Future versions of CMake may detect attempts to use this keyword from places other than a dependency provider and halt with a fatal error.

Full Signature

find_package(<PackageName> [version] [EXACT] [QUIET]
             [REQUIRED] [[COMPONENTS] [components...]]
             [OPTIONAL_COMPONENTS components...]
             [CONFIG|NO_MODULE]
             [GLOBAL]
             [NO_POLICY_SCOPE]
             [BYPASS_PROVIDER]
             [NAMES name1 [name2 ...]]
             [CONFIGS config1 [config2 ...]]
             [HINTS path1 [path2 ... ]]
             [PATHS path1 [path2 ... ]]
             [REGISTRY_VIEW  (64|32|64_32|32_64|HOST|TARGET|BOTH)]
             [PATH_SUFFIXES suffix1 [suffix2 ...]]
             [NO_DEFAULT_PATH]
             [NO_PACKAGE_ROOT_PATH]
             [NO_CMAKE_PATH]
             [NO_CMAKE_ENVIRONMENT_PATH]
             [NO_SYSTEM_ENVIRONMENT_PATH]
             [NO_CMAKE_PACKAGE_REGISTRY]
             [NO_CMAKE_BUILDS_PATH] # Deprecated; does nothing.
             [NO_CMAKE_SYSTEM_PATH]
             [NO_CMAKE_INSTALL_PREFIX]
             [NO_CMAKE_SYSTEM_PACKAGE_REGISTRY]
             [CMAKE_FIND_ROOT_PATH_BOTH |
              ONLY_CMAKE_FIND_ROOT_PATH |
              NO_CMAKE_FIND_ROOT_PATH])

The CONFIG option, the synonymous NO_MODULE option, or the use of options not specified in the basic signature all enforce pure Config mode. In pure Config mode, the command skips Module mode search and proceeds at once with Config mode search.

Config mode search attempts to locate a configuration file provided by the package to be found. A cache entry called <PackageName>_DIR is created to hold the directory containing the file. By default, the command searches for a package with the name <PackageName>. If the NAMES option is given, the names following it are used instead of <PackageName>. The names are also considered when determining whether to redirect the call to a package provided by FetchContent.

The command searches for a file called <PackageName>Config.cmake or <lowercasePackageName>-config.cmake for each name specified. A replacement set of possible configuration file names may be given using the CONFIGS option. The Config Mode Search Procedure is specified below. Once found, any version constraint is checked, and if satisfied, the configuration file is read and processed by CMake. Since the file is provided by the package it already knows the location of package contents. The full path to the configuration file is stored in the cmake variable <PackageName>_CONFIG.

All configuration files which have been considered by CMake while searching for the package with an appropriate version are stored in the <PackageName>_CONSIDERED_CONFIGS variable, and the associated versions in the <PackageName>_CONSIDERED_VERSIONS variable.

If the package configuration file cannot be found CMake will generate an error describing the problem unless the QUIET argument is specified. If REQUIRED is specified and the package is not found a fatal error is generated and the configure step stops executing. If <PackageName>_DIR has been set to a directory not containing a configuration file CMake will ignore it and search from scratch.

Package maintainers providing CMake package configuration files are encouraged to name and install them such that the Config Mode Search Procedure outlined below will find them without requiring use of additional options.

Config Mode Search Procedure

Note

When Config mode is used, this search procedure is applied regardless of whether the full or basic signature was given.

New in version 3.24: All calls to find_package() (even in Module mode) first look for a config package file in the CMAKE_FIND_PACKAGE_REDIRECTS_DIR directory. The FetchContent module, or even the project itself, may write files to that location to redirect find_package() calls to content already provided by the project. If no config package file is found in that location, the search proceeds with the logic described below.

CMake constructs a set of possible installation prefixes for the package. Under each prefix several directories are searched for a configuration file. The tables below show the directories searched. Each entry is meant for installation trees following Windows (W), UNIX (U), or Apple (A) conventions:

Entry	Convention
<prefix>/	W
<prefix>/(cmake|CMake)/	W
<prefix>/<name>*/	W
<prefix>/<name>*/(cmake|CMake)/	W
<prefix>/<name>*/(cmake|CMake)/<name>*/ [1]	W
<prefix>/(lib/<arch>|lib*|share)/cmake/<name>*/	U
<prefix>/(lib/<arch>|lib*|share)/<name>*/	U
<prefix>/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/	U
<prefix>/<name>*/(lib/<arch>|lib*|share)/cmake/<name>*/	W/U
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/	W/U
<prefix>/<name>*/(lib/<arch>|lib*|share)/<name>*/(cmake|CMake)/	W/U

[1]

New in version 3.25.

On systems supporting macOS FRAMEWORK and BUNDLE, the following directories are searched for Frameworks or Application Bundles containing a configuration file:

Entry	Convention
<prefix>/<name>.framework/Resources/	A
<prefix>/<name>.framework/Resources/CMake/	A
<prefix>/<name>.framework/Versions/*/Resources/	A
<prefix>/<name>.framework/Versions/*/Resources/CMake/	A
<prefix>/<name>.app/Contents/Resources/	A
<prefix>/<name>.app/Contents/Resources/CMake/	A

In all cases the <name> is treated as case-insensitive and corresponds to any of the names specified (<PackageName> or names given by NAMES).

If at least one compiled language has been enabled, the architecture-specific lib/<arch> and lib* directories may be searched based on the compiler's target architecture, in the following order:

lib/<arch>

Searched if the CMAKE_LIBRARY_ARCHITECTURE variable is set.

lib64

Searched on 64 bit platforms (CMAKE_SIZEOF_VOID_P is 8) and the FIND_LIBRARY_USE_LIB64_PATHS property is set to TRUE.

lib32

Searched on 32 bit platforms (CMAKE_SIZEOF_VOID_P is 4) and the FIND_LIBRARY_USE_LIB32_PATHS property is set to TRUE.

libx32

Searched on platforms using the x32 ABI if the FIND_LIBRARY_USE_LIBX32_PATHS property is set to TRUE.

lib

Always searched.

Changed in version 3.24: On Windows platform, it is possible to include registry queries as part of the directories specified through HINTS and PATHS keywords, using a dedicated syntax. Such specifications will be ignored on all other platforms.

New in version 3.24: REGISTRY_VIEW can be specified to manage Windows registry queries specified as part of PATHS and HINTS.

Specify which registry views must be queried. This option is only meaningful on Windows platforms and will be ignored on other ones. When not specified, the TARGET view is used when the CMP0134 policy is NEW. Refer to CMP0134 for the default view when the policy is OLD.

64

Query the 64-bit registry. On 32-bit Windows, it always returns the string /REGISTRY-NOTFOUND.

32

Query the 32-bit registry.

64_32

Query both views (64 and 32) and generate a path for each.

32_64

Query both views (32 and 64) and generate a path for each.

HOST

Query the registry matching the architecture of the host: 64 on 64-bit Windows and 32 on 32-bit Windows.

TARGET

Query the registry matching the architecture specified by the CMAKE_SIZEOF_VOID_P variable. If not defined, fall back to HOST view.

BOTH

Query both views (32 and 64). The order depends on the following rules: If the CMAKE_SIZEOF_VOID_P variable is defined, use the following view depending on the content of this variable:

• 8: 64_32

• 4: 32_64

If the CMAKE_SIZEOF_VOID_P variable is not defined, rely on the architecture of the host:

• 64-bit: 64_32

• 32-bit: 32

If PATH_SUFFIXES is specified, the suffixes are appended to each (W) or (U) directory entry one-by-one.

This set of directories is intended to work in cooperation with projects that provide configuration files in their installation trees. Directories above marked with (W) are intended for installations on Windows where the prefix may point at the top of an application's installation directory. Those marked with (U) are intended for installations on UNIX platforms where the prefix is shared by multiple packages. This is merely a convention, so all (W) and (U) directories are still searched on all platforms. Directories marked with (A) are intended for installations on Apple platforms. The CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE variables determine the order of preference.

The set of installation prefixes is constructed using the following steps. If NO_DEFAULT_PATH is specified all NO_* options are enabled.

1. Search prefixes unique to the current <PackageName> being found. See policy CMP0074.

   New in version 3.12.

   Specifically, search prefixes specified by the following variables, in order:

   1. <PackageName>_ROOT CMake variable, where <PackageName> is the case-preserved package name.

   2. <PACKAGENAME>_ROOT CMake variable, where <PACKAGENAME> is the upper-cased package name. See policy CMP0144.

      New in version 3.27.

   3. <PackageName>_ROOT environment variable, where <PackageName> is the case-preserved package name.

   4. <PACKAGENAME>_ROOT environment variable, where <PACKAGENAME> is the upper-cased package name. See policy CMP0144.

      New in version 3.27.

   The package root variables are maintained as a stack so if called from within a find module, root paths from the parent's find module will also be searched after paths for the current package. This can be skipped if NO_PACKAGE_ROOT_PATH is passed or by setting the CMAKE_FIND_USE_PACKAGE_ROOT_PATH to FALSE.

2. Search paths specified in cmake-specific cache variables. These are intended to be used on the command line with a -DVAR=VALUE. The values are interpreted as semicolon-separated lists. This can be skipped if NO_CMAKE_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_PATH to FALSE:

   • CMAKE_PREFIX_PATH

   • CMAKE_FRAMEWORK_PATH

   • CMAKE_APPBUNDLE_PATH

3. Search paths specified in cmake-specific environment variables. These are intended to be set in the user's shell configuration, and therefore use the host's native path separator (; on Windows and : on UNIX). This can be skipped if NO_CMAKE_ENVIRONMENT_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH to FALSE:

   • <PackageName>_DIR

   • CMAKE_PREFIX_PATH

   • CMAKE_FRAMEWORK_PATH

   • CMAKE_APPBUNDLE_PATH

4. Search paths specified by the HINTS option. These should be paths computed by system introspection, such as a hint provided by the location of another item already found. Hard-coded guesses should be specified with the PATHS option.

5. Search the standard system environment variables. This can be skipped if NO_SYSTEM_ENVIRONMENT_PATH is passed or by setting the CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH to FALSE. Path entries ending in /bin or /sbin are automatically converted to their parent directories:

   • PATH

6. Search paths stored in the CMake User Package Registry. This can be skipped if NO_CMAKE_PACKAGE_REGISTRY is passed or by setting the variable CMAKE_FIND_USE_PACKAGE_REGISTRY to FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY to TRUE.

   See the cmake-packages(7) manual for details on the user package registry.

7. Search cmake variables defined in the Platform files for the current system. The searching of CMAKE_INSTALL_PREFIX and CMAKE_STAGING_PREFIX can be skipped if NO_CMAKE_INSTALL_PREFIX is passed or by setting the CMAKE_FIND_USE_INSTALL_PREFIX to FALSE. All these locations can be skipped if NO_CMAKE_SYSTEM_PATH is passed or by setting the CMAKE_FIND_USE_CMAKE_SYSTEM_PATH to FALSE:

   • CMAKE_SYSTEM_PREFIX_PATH

   • CMAKE_SYSTEM_FRAMEWORK_PATH

   • CMAKE_SYSTEM_APPBUNDLE_PATH

   The platform paths that these variables contain are locations that typically include installed software. An example being /usr/local for UNIX based platforms.

8. Search paths stored in the CMake System Package Registry. This can be skipped if NO_CMAKE_SYSTEM_PACKAGE_REGISTRY is passed or by setting the CMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY variable to FALSE or the deprecated variable CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY to TRUE.

   See the cmake-packages(7) manual for details on the system package registry.

9. Search paths specified by the PATHS option. These are typically hard-coded guesses.

The CMAKE_IGNORE_PATH, CMAKE_IGNORE_PREFIX_PATH, CMAKE_SYSTEM_IGNORE_PATH and CMAKE_SYSTEM_IGNORE_PREFIX_PATH variables can also cause some of the above locations to be ignored.

New in version 3.16: Added the CMAKE_FIND_USE_<CATEGORY> variables to globally disable various search locations.

The CMake variable CMAKE_FIND_ROOT_PATH specifies one or more directories to be prepended to all other search directories. This effectively "re-roots" the entire search under given locations. Paths which are descendants of the CMAKE_STAGING_PREFIX are excluded from this re-rooting, because that variable is always a path on the host system. By default the CMAKE_FIND_ROOT_PATH is empty.

The CMAKE_SYSROOT variable can also be used to specify exactly one directory to use as a prefix. Setting CMAKE_SYSROOT also has other effects. See the documentation for that variable for more.

These variables are especially useful when cross-compiling to point to the root directory of the target environment and CMake will search there too. By default at first the directories listed in CMAKE_FIND_ROOT_PATH are searched, then the CMAKE_SYSROOT directory is searched, and then the non-rooted directories will be searched. The default behavior can be adjusted by setting CMAKE_FIND_ROOT_PATH_MODE_PACKAGE. This behavior can be manually overridden on a per-call basis using options:

CMAKE_FIND_ROOT_PATH_BOTH

Search in the order described above.

NO_CMAKE_FIND_ROOT_PATH

Do not use the CMAKE_FIND_ROOT_PATH variable.

ONLY_CMAKE_FIND_ROOT_PATH

Search only the re-rooted directories and directories below CMAKE_STAGING_PREFIX.

The default search order is designed to be most-specific to least-specific for common use cases. Projects may override the order by simply calling the command multiple times and using the NO_* options:

find_package (<PackageName> PATHS paths... NO_DEFAULT_PATH)
find_package (<PackageName>)

Once one of the calls succeeds the result variable will be set and stored in the cache so that no call will search again.

By default the value stored in the result variable will be the path at which the file is found. The CMAKE_FIND_PACKAGE_RESOLVE_SYMLINKS variable may be set to TRUE before calling find_package in order to resolve symbolic links and store the real path to the file.

Every non-REQUIRED find_package call can be disabled or made REQUIRED:

• Setting the CMAKE_DISABLE_FIND_PACKAGE_<PackageName> variable to TRUE disables the package. This also disables redirection to a package provided by FetchContent.

• Setting the CMAKE_REQUIRE_FIND_PACKAGE_<PackageName> variable to TRUE makes the package REQUIRED.

Setting both variables to TRUE simultaneously is an error.

Config Mode Version Selection

Note

When Config mode is used, this version selection process is applied regardless of whether the full or basic signature was given.

When the [version] argument is given, Config mode will only find a version of the package that claims compatibility with the requested version (see format specification). If the EXACT option is given, only a version of the package claiming an exact match of the requested version may be found. CMake does not establish any convention for the meaning of version numbers. Package version numbers are checked by "version" files provided by the packages themselves or by FetchContent. For a candidate package configuration file <config-file>.cmake the corresponding version file is located next to it and named either <config-file>-version.cmake or <config-file>Version.cmake. If no such version file is available then the configuration file is assumed to not be compatible with any requested version. A basic version file containing generic version matching code can be created using the CMakePackageConfigHelpers module. When a version file is found it is loaded to check the requested version number. The version file is loaded in a nested scope in which the following variables have been defined:

PACKAGE_FIND_NAME

The <PackageName>

PACKAGE_FIND_VERSION

Full requested version string

PACKAGE_FIND_VERSION_MAJOR

Major version if requested, else 0

PACKAGE_FIND_VERSION_MINOR

Minor version if requested, else 0

PACKAGE_FIND_VERSION_PATCH

Patch version if requested, else 0

PACKAGE_FIND_VERSION_TWEAK

Tweak version if requested, else 0

PACKAGE_FIND_VERSION_COUNT

Number of version components, 0 to 4

When a version range is specified, the above version variables will hold values based on the lower end of the version range. This is to preserve compatibility with packages that have not been implemented to expect version ranges. In addition, the version range will be described by the following variables:

PACKAGE_FIND_VERSION_RANGE

Full requested version range string

PACKAGE_FIND_VERSION_RANGE_MIN

This specifies whether the lower end point of the version range should be included or excluded. Currently, the only supported value for this variable is INCLUDE.

PACKAGE_FIND_VERSION_RANGE_MAX

This specifies whether the upper end point of the version range should be included or excluded. The supported values for this variable are INCLUDE and EXCLUDE.

PACKAGE_FIND_VERSION_MIN

Full requested version string of the lower end point of the range

PACKAGE_FIND_VERSION_MIN_MAJOR

Major version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_MINOR

Minor version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_PATCH

Patch version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_TWEAK

Tweak version of the lower end point if requested, else 0

PACKAGE_FIND_VERSION_MIN_COUNT

Number of version components of the lower end point, 0 to 4

PACKAGE_FIND_VERSION_MAX

Full requested version string of the upper end point of the range

PACKAGE_FIND_VERSION_MAX_MAJOR

Major version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_MINOR

Minor version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_PATCH

Patch version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_TWEAK

Tweak version of the upper end point if requested, else 0

PACKAGE_FIND_VERSION_MAX_COUNT

Number of version components of the upper end point, 0 to 4

Regardless of whether a single version or a version range is specified, the variable PACKAGE_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as specified.

The version file checks whether it satisfies the requested version and sets these variables:

PACKAGE_VERSION

Full provided version string

PACKAGE_VERSION_EXACT

True if version is exact match

PACKAGE_VERSION_COMPATIBLE

True if version is compatible

PACKAGE_VERSION_UNSUITABLE

True if unsuitable as any version

These variables are checked by the find_package command to determine whether the configuration file provides an acceptable version. They are not available after the find_package call returns. If the version is acceptable the following variables are set:

<PackageName>_VERSION

Full provided version string

<PackageName>_VERSION_MAJOR

Major version if provided, else 0

<PackageName>_VERSION_MINOR

Minor version if provided, else 0

<PackageName>_VERSION_PATCH

Patch version if provided, else 0

<PackageName>_VERSION_TWEAK

Tweak version if provided, else 0

<PackageName>_VERSION_COUNT

Number of version components, 0 to 4

and the corresponding package configuration file is loaded. When multiple package configuration files are available whose version files claim compatibility with the version requested it is unspecified which one is chosen: unless the variable CMAKE_FIND_PACKAGE_SORT_ORDER is set no attempt is made to choose a highest or closest version number.

To control the order in which find_package checks for compatibility use the two variables CMAKE_FIND_PACKAGE_SORT_ORDER and CMAKE_FIND_PACKAGE_SORT_DIRECTION. For instance in order to select the highest version one can set

SET(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
SET(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)

before calling find_package.

Package File Interface Variables

When loading a find module or package configuration file find_package defines variables to provide information about the call arguments (and restores their original state before returning):

CMAKE_FIND_PACKAGE_NAME

The <PackageName> which is searched for

<PackageName>_FIND_REQUIRED

True if REQUIRED option was given

<PackageName>_FIND_QUIETLY

True if QUIET option was given

<PackageName>_FIND_REGISTRY_VIEW

The requested view if REGISTRY_VIEW option was given

<PackageName>_FIND_VERSION

Full requested version string

<PackageName>_FIND_VERSION_MAJOR

Major version if requested, else 0

<PackageName>_FIND_VERSION_MINOR

Minor version if requested, else 0

<PackageName>_FIND_VERSION_PATCH

Patch version if requested, else 0

<PackageName>_FIND_VERSION_TWEAK

Tweak version if requested, else 0

<PackageName>_FIND_VERSION_COUNT

Number of version components, 0 to 4

<PackageName>_FIND_VERSION_EXACT

True if EXACT option was given

<PackageName>_FIND_COMPONENTS

List of specified components (required and optional)

<PackageName>_FIND_REQUIRED_<c>

True if component <c> is required, false if component <c> is optional

When a version range is specified, the above version variables will hold values based on the lower end of the version range. This is to preserve compatibility with packages that have not been implemented to expect version ranges. In addition, the version range will be described by the following variables:

<PackageName>_FIND_VERSION_RANGE

Full requested version range string

<PackageName>_FIND_VERSION_RANGE_MIN

This specifies whether the lower end point of the version range is included or excluded. Currently, INCLUDE is the only supported value.

<PackageName>_FIND_VERSION_RANGE_MAX

This specifies whether the upper end point of the version range is included or excluded. The possible values for this variable are INCLUDE or EXCLUDE.

<PackageName>_FIND_VERSION_MIN

Full requested version string of the lower end point of the range

<PackageName>_FIND_VERSION_MIN_MAJOR

Major version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_MINOR

Minor version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_PATCH

Patch version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_TWEAK

Tweak version of the lower end point if requested, else 0

<PackageName>_FIND_VERSION_MIN_COUNT

Number of version components of the lower end point, 0 to 4

<PackageName>_FIND_VERSION_MAX

Full requested version string of the upper end point of the range

<PackageName>_FIND_VERSION_MAX_MAJOR

Major version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_MINOR

Minor version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_PATCH

Patch version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_TWEAK

Tweak version of the upper end point if requested, else 0

<PackageName>_FIND_VERSION_MAX_COUNT

Number of version components of the upper end point, 0 to 4

Regardless of whether a single version or a version range is specified, the variable <PackageName>_FIND_VERSION_COMPLETE will be defined and will hold the full requested version string as specified.

In Module mode the loaded find module is responsible to honor the request detailed by these variables; see the find module for details. In Config mode find_package handles REQUIRED, QUIET, and [version] options automatically but leaves it to the package configuration file to handle components in a way that makes sense for the package. The package configuration file may set <PackageName>_FOUND to false to tell find_package that component requirements are not satisfied.