Calls Visual Studio MSBuild command to build a .sln project:

from conans import ConanFile, MSBuild

class ExampleConan(ConanFile):

    def build(self):
        msbuild = MSBuild(self)"MyProject.sln")

Internally the MSBuild build helper uses VisualStudioBuildEnvironment to adjust the LIB and CL environment variables with all the information from the requirements: include directories, library names, flags etc. and then calls MSBuild.

You can adjust all the information from the requirements accessing to the build_env that it is a VisualStudioBuildEnvironment object:

 from conans import ConanFile, MSBuild

 class ExampleConan(ConanFile):

     def build(self):
         msbuild = MSBuild(self)
         msbuild.build_env.link_flags = []

To inject the flags corresponding to the compiler.runtime, build_type and compiler.cppstd settings, this build helper also generates a properties file (in the build folder) that is passed to :command:MSBuild with :command:/p:ForceImportBeforeCppTargets="conan_build.props".


class MSBuild(object):

    def __init__(self, conanfile)
  • conanfile (Required): ConanFile object. Usually self in a



A VisualStudioBuildEnvironment object with the needed environment variables.



def build(self, project_file, targets=None, upgrade_project=True, build_type=None, arch=None,
          parallel=True, force_vcvars=False, toolset=None, platforms=None, use_env=True,
          vcvars_ver=None, winsdk_version=None, properties=None, output_binary_log=None,
          property_file_name=None, verbosity=None, definitions=None,

Builds Visual Studio project with the given parameters.

  • project_file (Required): Path to the .sln file.

  • targets (Optional, Defaulted to None): Sets /target flag to the specified list of targets to build.

  • upgrade_project (Optional, Defaulted to True): Will call devenv /upgrade to upgrade the solution to your current Visual Studio.

  • build_type (Optional, Defaulted to None): Sets /p:Configuration flag to the specified value. It will override the value from settings.build_type.

  • arch (Optional, Defaulted to None): Sets /p:Platform flag to the specified value. It will override the value from settings.arch. This value (or the settings.arch one if not overridden) will be used as the key for the msvc_arch dictionary that returns the final string used for the /p:Platform flag (see platforms argument documentation below).

  • parallel (Optional, Defaulted to True): Will use the configured number of cores in the conan.conf file or tools.cpu_count():

    • In the solution: Building the solution with the projects in parallel. (/m: parameter).

    • CL compiler: Building the sources in parallel. (/MP: compiler flag).

  • force_vcvars (Optional, Defaulted to False): Will ignore if the environment is already set for a different Visual Studio version.

  • toolset (Optional, Defaulted to None): Sets /p:PlatformToolset to the specified toolset. When None it will apply the setting compiler.toolset if specified. When False it will skip adjusting the /p:PlatformToolset.

  • platforms (Optional, Defaulted to None): This dictionary will update the default one (see msvc_arch below) and will be used to get the mapping of architectures to platforms from the Conan naming to another one. It is useful for Visual Studio solutions that have a different naming in architectures. Example: platforms={"x86":"Win32"} (Visual solution uses “Win32” instead of “x86”).

    msvc_arch = {'x86': 'x86',
                 'x86_64': 'x64',
                 'armv7': 'ARM',
                 'armv8': 'ARM64'}
  • use_env (Optional, Defaulted to True: Sets /p:UseEnv=true flag. Note that this setting does not guarantee that environment variables from Conan will not be used by the compiler or linker. This is an MSBuild setting which simply specifies the behavior when environment variables conflict with equivalent properties from the project (via .vcxproj, .props or .targets files). Conan will still apply the relevant compiler and linker environment variables when spawning the MSBuild process. For example, if use_env=False is specified and if there is no AdditionalDependencies variable defined in the project, the LINK environment variable passed by Conan will still be used by the linker because it technically doesn’t conflict with the project variable.

  • vcvars_ver (Optional, Defaulted to None): Specifies the Visual Studio compiler toolset to use.

  • winsdk_version (Optional, Defaulted to None): Specifies the version of the Windows SDK to use.

  • properties (Optional, Defaulted to None): Dictionary with new properties, for each element in the dictionary {name: value} it will append a /p:name="value" option.

  • output_binary_log (Optional, Defaulted to None): Sets /bl flag. If set to True then MSBuild will output a binary log file called msbuild.binlog in the working directory. It can also be used to set the name of log file like this output_binary_log="my_log.binlog". This parameter is only supported starting from MSBuild version 15.3 and onwards.

  • property_file_name (Optional, Defaulted to None): Sets p:ForceImportBeforeCppTargets. When None it will generate a file named conan_build.props. You can specify a different name for the generated properties file.

  • verbosity (Optional, Defaulted to None): Sets the /verbosity flag to the specified verbosity level. Possible values are "quiet", "minimal", "normal", "detailed" and "diagnostic".

  • definitions (Optional, Defaulted to None): Dictionary with additional compiler definitions to be applied during the build. Use a dictionary with the desired key and its value set to None to set a compiler definition with no value.

  • user_property_file_name (Optional, Defaulted to None): Filename or list of filenames of user properties files to be automatically passed to the build command. These files have priority over the conan_build.props file (user can override that file values), and if a list of file names is provided, later file names also have priority over the former ones. These filenames will be passed, together with conan_build.props files as /p:ForceImportBeforeCppTargets argument.


The MSBuild() build helper will, before calling to MSBuild, call tools.vcvars_command() to adjust the environment according to the settings. When cross-building from x64 to x86 the toolchain by default is x86. If you want to use amd64_x86 instead, set the environment variable PreferredToolArchitecture=x64.


Returns a string command calling MSBuild.

def get_command(self, project_file, props_file_path=None, targets=None, upgrade_project=True,
                build_type=None, arch=None, parallel=True, toolset=None, platforms=None,
                use_env=False, properties=None, output_binary_log=None, verbosity=None,
  • props_file_path (Optional, Defaulted to None): Path to a property file to be included in the compilation command. This parameter is automatically set by the build() method to set the runtime from settings.

  • Same parameters as the build() method.


Static method that returns the version of MSBuild for the specified settings.

def get_version(settings)

Result is returned in a conans.model.Version object as it is evaluated by the command line. It will raise an exception if it cannot resolve it to a valid result.

  • settings (Required): Conanfile settings. Use self.settings.


Prepares the needed environment variables to invoke the Visual Studio compiler. Use it together with tools.vcvars_command().

 from conans import ConanFile, VisualStudioBuildEnvironment

 class ExampleConan(ConanFile):


     def build(self):
         if self.settings.compiler == "Visual Studio":
             env_build = VisualStudioBuildEnvironment(self)
             with tools.environment_append(env_build.vars):
                 vcvars = tools.vcvars_command(self.settings)
       '%s && cl /c /EHsc hello.cpp' % vcvars)
       '%s && lib hello.obj -OUT:hello.lib' % vcvars

You can adjust the automatically filled attributes:

 def build(self):
     if self.settings.compiler == "Visual Studio":
     env_build = VisualStudioBuildEnvironment(self)
     env_build.link_flags = []
     with tools.environment_append(env_build.vars):
         vcvars = tools.vcvars_command(self.settings)'%s && cl /c /EHsc hello.cpp' % vcvars)'%s && lib hello.obj -OUT:hello.lib' % vcvars


class VisualStudioBuildEnvironment(object):

    def __init__(self, conanfile, with_build_type_flags=True)
  • conanfile (Required): ConanFile object. Usually self in a

  • with_build_type_flags (Optional, Defaulted to True): If True, it adjusts the compiler flags according to the build_type setting. e.g: -Zi, -Ob0, -Od

Environment variables




Library paths separated with “;”


“/I” flags with include directories, Runtime (/MT, /MD…), Definitions (/DXXX), and any other C and CXX flags.



List with directories of include paths.


List with directories of libraries.


List with definitions from requirements’ cpp_info.defines.


List with directories from settings.compiler.runtime.


List with flags from requirements’ cpp_info.cflags.


List with cxx flags from requirements’ cpp_info.cxxflags.


This property contains the flag corresponding to the C++ standard. If you are still using the deprecated setting cppstd (see How to manage C++ standard [EXPERIMENTAL]) and you are not providing any value for this setting, the property will be None.


Defaulted to False.

Sets the flag /MP in order to compile the sources in parallel using cores found by tools.cpu_count().

See also

Read more about tools.environment_append().