conan install

$ conan install [-h] [-g GENERATOR] [-if INSTALL_FOLDER] [-m [MANIFESTS]]
                [-mi [MANIFESTS_INTERACTIVE]] [-v [VERIFY]]
                [--no-imports] [-j JSON] [-b [BUILD]] [-r REMOTE] [-u]
                [-l [LOCKFILE]] [--lockfile-out LOCKFILE_OUT] [-e ENV_HOST] [-e:b ENV_BUILD]
                [-e:h ENV_HOST] [-o OPTIONS_HOST] [-o:b OPTIONS_BUILD]
                [-o:h OPTIONS_HOST] [-pr PROFILE_HOST]
                [-pr:b PROFILE_BUILD] [-pr:h PROFILE_HOST]
                [-s SETTINGS_HOST] [-s:b SETTINGS_BUILD]
                [-s:h SETTINGS_HOST]
                [--lockfile-node-id LOCKFILE_NODE_ID]
                path_or_reference [reference]

Installs the requirements specified in a recipe (conanfile.py or conanfile.txt).

It can also be used to install a concrete package specifying a reference. If any requirement is not found in the local cache, it will retrieve the recipe from a remote, looking for it sequentially in the configured remotes. When the recipes have been downloaded it will try to download a binary package matching the specified settings, only from the remote from which the recipe was retrieved. If no binary package is found, it can be built from sources using the ‘–build’ option. When the package is installed, Conan will write the files for the specified generators.

positional arguments:
  path_or_reference     Path to a folder containing a recipe (conanfile.py or
                        conanfile.txt) or to a recipe file. e.g.,
                        ./my_project/conanfile.txt. It could also be a
                        reference
  reference             Reference for the conanfile path of the first
                        argument: user/channel, version@user/channel or
                        pkg/version@user/channel(if name or version declared
                        in conanfile.py, they should match)

optional arguments:
  -h, --help            show this help message and exit
  -g GENERATOR, --generator GENERATOR
                        Generators to use
  -if INSTALL_FOLDER, --install-folder INSTALL_FOLDER
                        Use this directory as the directory where to put the
                        generatorfiles. e.g., conaninfo/conanbuildinfo.txt
  -m [MANIFESTS], --manifests [MANIFESTS]
                        Install dependencies manifests in folder for later
                        verify. Default folder is .conan_manifests, but can be
                        changed
  -mi [MANIFESTS_INTERACTIVE], --manifests-interactive [MANIFESTS_INTERACTIVE]
                        Install dependencies manifests in folder for later
                        verify, asking user for confirmation. Default folder
                        is .conan_manifests, but can be changed
  -v [VERIFY], --verify [VERIFY]
                        Verify dependencies manifests against stored ones
  --no-imports          Install specified packages but avoid running imports
  -j JSON, --json JSON  Path to a json file where the install information will
                        be written
  -b [BUILD], --build [BUILD]
                        Optional, specify which packages to build from source.
                        Combining multiple '--build' options on one command
                        line is allowed. For dependencies, the optional
                        'build_policy' attribute in their conanfile.py takes
                        precedence over the command line parameter. Possible
                        parameters: --build Force build for all packages, do
                        not use binary packages. --build=never Disallow build
                        for all packages, use binary packages or fail if a
                        binary package is not found. Cannot be combined with
                        other '--build' options. --build=missing Build
                        packages from source whose binary package is not
                        found. --build=outdated Build packages from source
                        whose binary package was not generated from the latest
                        recipe or is not found. --build=cascade Build packages
                        from source that have at least one dependency being
                        built from source. --build=[pattern] Build packages
                        from source whose package reference matches the
                        pattern. The pattern uses 'fnmatch' style wildcards.
                        Default behavior: If you omit the '--build' option,
                        the 'build_policy' attribute in conanfile.py will be
                        used if it exists, otherwise the behavior is like '--
                        build=never'.
  -r REMOTE, --remote REMOTE
                        Look in the specified remote server
  -u, --update          Will check the remote and in case a newer version
                        and/or revision of the dependencies exists there, it
                        will install those in the local cache. When using
                        version ranges, it will install the latest version
                        that satisfies the range. Also, if using revisions, it
                        will update to the latest revision for the resolved
                        version range.
  -l [LOCKFILE], --lockfile [LOCKFILE]
                        Path to a lockfile or folder containing 'conan.lock'
                        file. Lockfile can be updated if packages change
  -e ENV_HOST, --env ENV_HOST
                        Environment variables that will be set during the
                        package build (host machine). e.g.: -e
                        CXX=/usr/bin/clang++
  -e:b ENV_BUILD, --env:build ENV_BUILD
                        Environment variables that will be set during the
                        package build (build machine). e.g.: -e:b
                        CXX=/usr/bin/clang++
  -e:h ENV_HOST, --env:host ENV_HOST
                        Environment variables that will be set during the
                        package build (host machine). e.g.: -e:h
                        CXX=/usr/bin/clang++
  -o OPTIONS_HOST, --options OPTIONS_HOST
                        Define options values (host machine), e.g.: -o
                        Pkg:with_qt=true
  -o:b OPTIONS_BUILD, --options:build OPTIONS_BUILD
                        Define options values (build machine), e.g.: -o:b
                        Pkg:with_qt=true
  -o:h OPTIONS_HOST, --options:host OPTIONS_HOST
                        Define options values (host machine), e.g.: -o:h
                        Pkg:with_qt=true
  -pr PROFILE_HOST, --profile PROFILE_HOST
                        Apply the specified profile to the host machine
  -pr:b PROFILE_BUILD, --profile:build PROFILE_BUILD
                        Apply the specified profile to the build machine
  -pr:h PROFILE_HOST, --profile:host PROFILE_HOST
                        Apply the specified profile to the host machine
  -s SETTINGS_HOST, --settings SETTINGS_HOST
                        Settings to build the package, overwriting the
                        defaults (host machine). e.g.: -s compiler=gcc
  -s:b SETTINGS_BUILD, --settings:build SETTINGS_BUILD
                        Settings to build the package, overwriting the
                        defaults (build machine). e.g.: -s:b compiler=gcc
  -s:h SETTINGS_HOST, --settings:host SETTINGS_HOST
                        Settings to build the package, overwriting the
                        defaults (host machine). e.g.: -s:h compiler=gcc
  --lockfile-node-id LOCKFILE_NODE_ID
                    NodeID of the referenced package in the lockfile

conan install executes methods of a conanfile.py in the following order:

  1. config_options()
  2. configure()
  3. requirements()
  4. package_id()
  5. package_info()
  6. deploy()

Note this describes the process of installing a pre-built binary package. If the package has to be built, conan install --build executes the following:

  1. config_options()
  2. configure()
  3. requirements()
  4. package_id()
  5. build_requirements()
  6. build_id()
  7. system_requirements()
  8. source()
  9. imports()
  10. build()
  11. package()
  12. package_info()
  13. deploy()

Examples

  • Install a package requirement from a conanfile.txt, saved in your current directory with one option and setting (other settings will be defaulted as defined in <userhome>/.conan/profiles/default):

    $ conan install . -o pkg_name:use_debug_mode=on -s compiler=clang
    
  • Install the requirements defined in a conanfile.py file in your current directory, with the default settings in default profile <userhome>/.conan/profiles/default, and specifying the version, user and channel (as they might be used in the recipe):

    class Pkg(ConanFile):
       name = "mypkg"
       # see, no version defined!
       def requirements(self):
           # this trick allow to depend on packages on your same user/channel
           self.requires("dep/0.3@%s/%s" % (self.user, self.channel))
    
       def build(self):
           if self.version == "myversion":
               # something specific for this version of the package.
    
    $ conan install . myversion@someuser/somechannel
    

    Those values are cached in a file, so later calls to local commands like conan build can find and use this version, user and channel data.

  • Install the opencv/4.1.1@conan/stable reference with its default options and default settings from <userhome>/.conan/profiles/default:

    $ conan install opencv/4.1.1@conan/stable
    
  • Install the opencv/4.1.1@conan/stable reference updating the recipe and the binary package if new upstream versions are available:

    $ conan install opencv/4.1.1@conan/stable --update
    

build options

Both the conan install and create commands accept --build options to specify which packages to build from source. Combining multiple --build options on one command line is allowed, where a package is built from source if at least one of the given build options selects it for the build. For dependencies, the optional build_policy attribute in their conanfile.py can override the behavior of the given command line parameters. Possible values are:

  • --build: Always build everything from source. Produces a clean re-build of all packages. and transitively dependent packages

  • --build=never: Conan will not try to build packages when the requested configuration does not match, in which case it will throw an error. This option can not be combined with other --build options.

  • --build=missing: Conan will try to build packages from source whose binary package was not found in the requested configuration on any of the active remotes or the cache.

  • --build=outdated: Conan will try to build packages from source whose binary package was not built with the current recipe or when missing the binary package.

  • --build=cascade: Conan selects packages for the build where at least one of its dependencies is selected for the build. This is useful to rebuild packages that, directly or indirectly, depend on changed packages.

  • --build=[pattern]: A fnmatch case-sensitive pattern of a package reference or only the package name. Conan will force the build of the packages whose reference matches the given pattern. Several patterns can be specified, chaining multiple options:

    • e.g., --build=pattern1 --build=pattern2 can be used to specify more than one pattern.
    • e.g., --build=zlib will match any package named zlib (same as zlib/*).
    • e.g., --build=z*@conan/stable will match any package starting with z with conan/stable as user/channel.

If you omit the --build option, the build_policy attribute in conanfile.py will be looked up. If it is set to missing or always, this build option will be used, otherwise the command will behave like --build=never was set.

env variables

With the -e parameters you can define:

  • Global environment variables (-e SOME_VAR="SOME_VALUE"). These variables will be defined before the build step in all the packages and will be cleaned after the build execution.
  • Specific package environment variables (-e zlib:SOME_VAR="SOME_VALUE"). These variables will be defined only in the specified packages (e.g., zlib).

You can specify this variables not only for your direct requires but for any package in the dependency graph.

If you want to define an environment variable but you want to append the variables declared in your requirements you can use the [] syntax:

$ conan install . -e PATH=[/other/path]

This way the first entry in the PATH variable will be /other/path but the PATH values declared in the requirements of the project will be appended at the end using the system path separator.

settings

With the -s parameters you can define:

  • Global settings (-s compiler="Visual Studio"). Will apply to all the requires.
  • Specific package settings (-s zlib:compiler="MinGW"). Those settings will be applied only to the specified packages. They accept patterns too, like -s *@myuser/*:compiler=MinGW, which means that packages that have the username “myuser” will use MinGW as compiler.

You can specify custom settings not only for your direct requires but for any package in the dependency graph.

options

With the -o parameters you can only define specific package options.

$ conan install . -o zlib:shared=True
$ conan install . -o zlib:shared=True -o bzip2:option=132
# you can also apply the same options to many packages with wildcards:
$ conan install . -o *:shared=True

Note

You can use profiles files to create predefined sets of settings, options and environment variables.

reference

An optional positional argument, if used the first argument should be a path. If the reference specifies name and/or version, and they are also declared in the conanfile.py, they should match, otherwise, an error will be raised.

$ conan install . # OK, user and channel will be None
$ conan install . user/testing # OK
$ conan install . version@user/testing # OK
$ conan install . pkg/version@user/testing # OK
$ conan install pkg/version@user/testing user/channel # Error, first arg is not a path

lockfiles

The install command accepts several arguments related to lockfiles:

  • --lockfile=<path-to-lockfile>: The conan install ... --lockfile=path/to/file.lock command will provide an input lockfile to the command. Versions, revisions, and other data contained in that lockfile will be respected. If something has changed locally that diverges with respect the locked information in the lockfile, the command will fail.
  • --lockfile-out=<path-to-lockfile>: This argument will define the filename of the resulting install operation. If the input lockfile has not completely locked something, and the install command can, for example, build some dependency from source with the --build=<dep-name> argument, this will provide new data, like a new package revision. This new data can be captured and locked in the output lockfile.
  • --lockfile-node-id=<node-id>: Experimental, subject to breaking changes. In some cases, it is impossible to reference a package in the dependency graph by name or reference, because there might be several instances of it with the same one. This could happen with some special type of requirements, like build-requires or private requires. Providing the node-id, as defined in the lockfile file, can define without any ambiguity the package in the graph that the command is referencing.

Note

Installation of binaries can be accelerated setting up parallel downloads with the general.parallel_download experimental configuration in conan.conf.