conan install

$ conan install [-h] [-g GENERATOR] [-if INSTALL_FOLDER] [-m [MANIFESTS]]
                [-mi [MANIFESTS_INTERACTIVE]] [-v [VERIFY]]
                [--no-imports] [-j JSON] [-b [BUILD]] [-e ENV]
                [-o OPTIONS] [-pr PROFILE] [-r REMOTE] [-s SETTINGS] [-u]
                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 build 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, use it to choose if you want to build from
                        sources: --build Build all from sources, do not use
                        binary packages. --build=never Never build, use binary
                        packages or fail if a binary package is not found.
                        --build=missing Build from code if a binary package is
                        not found. --build=cascade Will build from code all
                        the nodes with some dependency being built (for any
                        reason). Can be used together with any other build
                        policy. Useful to make sure that any new change
                        introduced in a dependency is incorporated by building
                        again the package. --build=outdated Build from code if
                        the binary is not built with the current recipe or
                        when missing binary package. --build=[pattern] Build
                        always these packages from source, but never build the
                        others. Allows multiple --build parameters. 'pattern'
                        is a fnmatch file pattern of a package reference.
                        Default behavior: If you don't specify anything, it
                        will be similar to '--build=never', but package
                        recipes can override it with their 'build_policy'
                        attribute in the conanfile.py.
  -e ENV, --env ENV     Environment variables that will be set during the
                        package build, -e CXX=/usr/bin/clang++
  -o OPTIONS, --options OPTIONS
                        Define options values, e.g., -o Pkg:with_qt=true
  -pr PROFILE, --profile PROFILE
                        Apply the specified profile to the install command
  -r REMOTE, --remote REMOTE
                        Look in the specified remote server
  -s SETTINGS, --settings SETTINGS
                        Settings to build the package, overwriting the
                        defaults. e.g., -s compiler=gcc
  -u, --update          Check updates exist from upstream remotes

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

config_options()
configure()
requirements()
package_id()
package_info()
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:

config_options()
configure()
requirements()
package_id()
build_requirements()
build_id()
system_requirements()
source()
imports()
build()
package()
package_info()
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 PkgName: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/2.4.10@lasote/testing reference with its default options and default settings from <userhome>/.conan/profiles/default:
```
$ conan install opencv/2.4.10@lasote/testing
```
Install the OpenCV/2.4.10@lasote/testing reference updating the recipe and the binary package if new upstream versions are available:
```
$ conan install opencv/2.4.10@lasote/testing --update
```

build options

Both the conan install and create commands have options to specify whether conan should try to build things or not:

--build=never: This is the default option. It is not necessary to write it explicitly. Conan will not try to build packages when the requested configuration does not match, in which case it will throw an error.
--build=missing: Conan will try to build from source, all packages of which the requested configuration was not found on any of the active remotes.
--build=outdated: Conan will try to build from code if the binary is not built with the current recipe or when missing binary package.
--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.
--build: Always build everything from source. Produces a clean re-build of all packages and transitively dependent packages

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 PYTHONPATH=[/other/path]

This way the first entry in the PYTHONPATH variable will be /other/path but the PYTHONPATH 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.

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