ENVIRONMENT VARIABLES

XBUILD_EMIT_SOLUTION

If this variable is set, then the project file generated from a solution file is emitted.

XBUILD_LOG_REFERENCE_RESOLVER

References are resolved by trying a list of assembly search paths ($(AssemblySearchPaths)). If xbuild is unable to resolve a reference, then it logs details of why the various search paths failed. If this variable is set, then it logs the same even for references that were resolved successfully. These logs show up if the verbosity is set to detailed or higher.

MSBuildExtensionsPath

MSBuild extensions are usually installed in $(MSBuildExtensionsPath), which xbuild resolves to $prefix/lib/mono/xbuild . When used in Import, like:

  <Import Project="$(MSBuildExtensionsPath)\TestTargets.targets"/>

xbuild tries various values for the msbuild property $(MSBuildExtensionsPath), in order:

  1. Paths specified in the environment variable $MSBuildExtensionsPath.
  2. /Library/Frameworks/Mono.framework/External/xbuild on Mac OSX.
  3. $XDG_CONFIG_HOME/xbuild/tasks (or Environment.SpecialFolder.ApplicationData)
  4. $prefix/lib/mono/xbuild (default location)

Anywhere else in the project files, $(MSBuildExtensionsPath) will always resolve to the default location. This is a xbuild-only feature. This is also applicable for the properties $(MSBuildExtensionsPath32) and $(MSBuildExtensionsPath64), and the environment variables have the corresponding names - MSBuildExtensionsPath32/64 .

XBUILD_FRAMEWORK_FOLDERS_PATH

With ToolsVersion 4.0, projects can target arbitrary frameworks referenced by TargetFrameworkMoniker, which is of the format:

  Identifier,Version=<version>[,Profile=<profile>]

Eg. ".NETFramework,Version=v4.0"

The 3 parts of the moniker are given by the msbuild properties:

  $(TargetFrameworkIdentifier), $(TargetFrameworkVersion) and $(TargetFrameworkProfile)

This moniker maps to a framework description file on disk:

  <framework_root>/Identifier/Version/[Profile]/RedistList/FrameworkList.xml

This file is used to determine the path where to find the framework assemblies for this particular framework.

Framework root here is configurable and is resolved in the following order:

  1. Paths specified in the environment variable $XBUILD_FRAMEWORK_FOLDERS_PATH
  2. /Library/Frameworks/Mono.framework/External/xbuild-frameworks on Mac OSX.
  3. MSBuild property $(TargetFrameworkRoot)
  4. $prefix/lib/mono/xbuild-frameworks (default location)

XBuild tries the paths given above, in order, till it finds a FrameworkList.xml for the moniker. Running with /v:detailed or higher verbosity will show the various paths that it tries.

The FrameworkList.xml itself just has a root element like:

  <FileList  Name=".NET Framework 3.5" TargetFrameworkDirectory="..\..\..\..\3.5" IncludeFramework="v3.0">
  </FileList>

Here the TargetFrameworkDirectory attribute specifies the directory where the assemblies for this particular framework can be found. If this is not set, then the parent of the folder containing the xml file is taken as the framework directory.

IncludeFramework attribute specifies the version of a framework (under the *same* $(TargetFrameworkIdentifier)) which should be included in the final list of Target framework directories.

XBUILD_COLORS

If this variable is set, it contains a string of the form "type=foreground,type=.." that specifies which color to use to display errors/warnings etc on some terminals. Type here can be:

        errors, warnings, messages or events
        events: These are project/target/task start and end event
                messages.

The possible colors for foreground are: black, red, brightred, green, brightgreen, yellow, brightyellow, blue, brightblue, magenta, brightmagenta, cyan, brightcyan, grey, white and brightwhite.

For example, you could set this variable from your shell:

        export XBUILD_COLORS
        XBUILD_COLORS=errors=brightred,warnings=blue

You can disable the built-in color scheme by setting this variable to "disable".