conan info

$ conan info [-h] [--paths] [-bo BUILD_ORDER] [-g GRAPH]
             [-if INSTALL_FOLDER] [-j [JSON]] [-n ONLY]
             [--package-filter [PACKAGE_FILTER]] [-db [DRY_BUILD]]
             [-b [BUILD]] [-e ENV] [-o OPTIONS] [-pr PROFILE] [-r REMOTE]
             [-s SETTINGS] [-u]
             path_or_reference

Gets information about the dependency graph of a recipe. It can be used with a recipe or a reference for any existing package in your local cache.

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

optional arguments:
  -h, --help            show this help message and exit
  --paths               Show package paths in local cache
  -bo BUILD_ORDER, --build-order BUILD_ORDER
                        given a modified reference, return an ordered list to
                        build (CI)
  -g GRAPH, --graph GRAPH
                        Creates file with project dependencies graph. It will
                        generate a DOT or HTML file depending on the filename
                        extension
  -if INSTALL_FOLDER, --install-folder INSTALL_FOLDER
                        local folder containing the conaninfo.txt and
                        conanbuildinfo.txt files (from a previous conan
                        install execution). Defaulted to current folder,
                        unless --profile, -s or -o is specified. If you
                        specify both install-folder and any setting/option it
                        will raise an error.
  -j [JSON], --json [JSON]
                        Path to a joon file where the information will be
                        written
  -n ONLY, --only ONLY  Show only the specified fields: "id", "build_id",
                        "remote", "url", "license", "requires", "update",
                        "required", "date", "author", "None". '--paths'
                        information can also be filtered with options
                        "export_folder", "build_folder", "package_folder",
                        "source_folder". Use '--only None' to show only
                        references.
  --package-filter [PACKAGE_FILTER]
                        Print information only for packages that match the
                        filter pattern e.g., MyPackage/1.2@user/channel or
                        MyPackage*
  -db [DRY_BUILD], --dry-build [DRY_BUILD]
                        Apply the --build argument to output the information,
                        as it would be done by the install command
  -b [BUILD], --build [BUILD]
                        Given a build policy, return an ordered list of
                        packages that would be built from sources during the
                        install command
  -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

Examples:

$ conan info .
$ conan info myproject_folder
$ conan info myproject_folder/conanfile.py
$ conan info Hello/1.0@user/channel

The output will look like:

Dependency/0.1@user/channel
 ID: 5ab84d6acfe1f23c4fae0ab88f26e3a396351ac9
 BuildID: None
 Remote: None
 URL: http://...
 License: MIT
 Updates: Version not checked
 Creation date: 2017-10-31 14:45:34
 Required by:
    Hello/1.0@user/channel

Hello/1.0@user/channel
 ID: 5ab84d6acfe1f23c4fa5ab84d6acfe1f23c4fa8
 BuildID: None
 Remote: None
 URL: http://...
 License: MIT
 Updates: Version not checked
 Required by:
    Project
 Requires:
    Hello0/0.1@user/channel

conan info builds the complete dependency graph, like conan install does. The main difference is that it doesn’t try to install or build the binaries, but the package recipes will be retrieved from remotes if necessary.

It is very important to note, that the info command outputs the dependency graph for a given configuration (settings, options), as the dependency graph can be different for different configurations. Then, the input to the conan info command is the same as conan install, the configuration can be specified directly with settings and options, or using profiles.

Also, if you did a previous conan install with a specific configuration, or maybe different installs with different configurations, you can reuse that information with the --install-folder argument:

$ # dir with a conanfile.txt
$ mkdir build_release && cd build_release
$ conan install .. --profile=gcc54release
$ cd .. && mkdir build_debug && cd build_debug
$ conan install .. --profile=gcc54debug
$ cd ..
$ conan info . --install-folder=build_release
> info for the release dependency graph install
$ conan info . --install-folder=build_debug
> info for the debug dependency graph install

It is possible to use the conan info command to extract useful information for Continuous Integration systems. More precisely, it has the --build-order, -bo option, that will produce a machine-readable output with an ordered list of package references, in the order they should be built. E.g., let’s assume that we have a project that depends on Boost and Poco, which in turn depends on OpenSSL and zlib transitively. So we can query our project with a reference that has changed (most likely due to a git push on that package):

$ conan info . -bo zlib/1.2.11@conan/stable
[zlib/1.2.11@conan/stable], [OpenSSL/1.0.2l@conan/stable], [Boost/1.60.0@lasote/stable, Poco/1.7.8p3@pocoproject/stable]

Note the result is a list of lists. When there is more than one element in one of the lists, it means that they are decoupled projects and they can be built in parallel by the CI system.

You can also specify the --build-order=ALL argument, if you want just to compute the whole dependency graph build order

$ conan info . --build-order=ALL
> [zlib/1.2.11@conan/stable], [OpenSSL/1.0.2l@conan/stable], [Boost/1.60.0@lasote/stable, Poco/1.7.8p3@pocoproject/stable]

Also you can get a list of nodes that would be built (simulation) in an install command specifying a build policy with the --build parameter.

E.g., if I try to install Boost/1.60.0@lasote/stable recipe with --build missing build policy and arch=x86, which libraries will be built?

$ conan info Boost/1.60.0@lasote/stable --build missing -s arch=x86
bzip2/1.0.6@lasote/stable, zlib/1.2.8@lasote/stable, Boost/1.60.0@lasote/stable

You can generate a graph of your dependencies, in dot or html formats:

$ conan info .. --graph=file.html
$ file.html # or open the file, double-click

../../../_images/info_deps_html_graph.png

The generated html output contains links to third party resources, the vis.js library (2 files: vis.min.js, vis.min.css). By default they are retrieved from cloudfare. However, for environments without internet connection, these files could be also used from the local cache and installed with conan config install by putting those files in the root of the configuration folder:

vis.min.js: Default link to “https://cdnjs.cloudflare.com/ajax/libs/vis/4.18.1/vis.min.js”
vis.min.css: Default link to “https://cdnjs.cloudflare.com/ajax/libs/vis/4.18.1/vis.min.css”

It is not necessary to modify the generated html file. Conan will automatically use the local paths to the cache files if present, or the internet ones if not.