Upgrading to conan 1.0

If you were using a 0.X conan version, there are some things to consider while upgrading. They are reflected in the changelog., but this section summarizes the most important changes here:

Command line changes

There has been a few things that will break existing usage (compared to 0.30). Most of them are in command line arguments, so they are relatively easy to fix. The most important one is that now most commands require the path to the conanfile folder or file, instead of using --path and --file arguments. Specifically, conan install, conan export and conan create will be the ones most affected:

# instead of --path=myfolder --file=myconanfile.py, now you can do:
$ conan install . # Note the "." is now mandatory
$ conan install folder/myconanfile.txt
$ conan install ../myconanfile.py
$ conan info .
$ conan create . user/channel
$ conan create . Pkg/0.1@user/channel
$ conan create mypkgconanfile.py Pkg/0.1@user/channel
$ conan export . user/channel
$ conan export . Pkg/0.1@user/channel
$ conan export myfolder/myconanfile.py Pkg/0.1@user/channel

This behavior aligns with the conan source, conan build, conan package commands, that all use the same arguments to locate the conanfile.py containing the logic to be run.

Now all commands read: command <origin-conanfile> ...

Also, all arguments to command line now use dash instead of underscore:

$ conan build .. --source-folder=../src  # not --source_folder


  • scopes were completely removed in conan 0.30.X
  • self.conanfile_directory has been removed. Use self.source_folder, self.build_folder, etc. instead
  • self.cpp_info, self.env_info and self.user_info scope has been reduced to only the package_info() method
  • gcc and ConfigureEnvironment were already removed in conan 0.30.1
  • werror doesn’t exist anymore. Now it is the builtin behavior.
  • Command test_package has been removed. Use conan create and conan test instead.
  • CMake helper only allows now (from conan 0.29). the CMake(self) syntax
  • conan package_files command was replaced in conan 0.28 by conan export-pkg command.

Settings and profiles. Gcc/CLang versioning

gcc and clang compilers have modified their versioning approach, from gcc > 5 and clang > 4, the minors are really bugfixes, and then they have binary compatibility. To adapt to this, conan now includes major version in the settings.yml default settings file:

    version: ["4.1", "4.4", "4.5", "4.6", "4.7", "4.8", "4.9",
              "5", "5.1", "5.2", "5.3", "5.4",
              "6", "6.1", "6.2", "6.3", "6.4",
              "7", "7.1", "7.2"]

Most package creators want to use the major-only settings, like -s compiler=gcc -s compiler.version=5, instead of specifying the minors too.

The default profile detection and creation has been modified accordingly, but if you have a default profile you may want to update it to reflect this:

Conan associated tools (conan-package-tools, conan.cmake) have been upgraded to accomodate this new defaults.

New features

  • Cross-compilation support with new default settings in settings.yml: os_build, arch_build, os_target, arch_target. They are automatically removed from the package_id computation, or kept if they are the only ones defined (as it happens usually with dev-tools packages). It is possible to keep them too with the self.info.include_build_settings() method (call it in your package_id() method).


Please don’t use cross-build settings os_build, arch_build for standard packages and libraries. They are only useful for packages that are used via build_requires, like cmake_installer or mingw_installer.

  • Model and utilities for Windows subsystems
        subsystem: [None, cygwin, msys, msys2, wsl]

This subsetting can be used by build helpers as CMake, to act accordingly.