c# - 无法在解决方案中构建某些项目？

Question

我收到以下消息，但我无法追踪到配置。有一些相关的文章，但似乎没有一个回答。

构建失败。未知的 LangVersion 字符串 ' '

如果我查看项目的构建属性，它会抛出异常，这似乎是构建错误的原因:

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Exception: Unknown LangVersion string ''
  at MonoDevelop.CSharp.Project.CSharpCompilerParameters.get_LangVersion () [0x00000] in <filename unknown>:0 
  at MonoDevelop.CSharp.Project.CompilerOptionsPanelWidget..ctor (MonoDevelop.Projects.DotNetProject project) [0x00000] in <filename unknown>:0 
  at MonoDevelop.CSharp.Project.CompilerOptionsPanel.CreatePanelWidget () [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.CreatePageWidget (MonoDevelop.Ide.Gui.Dialogs.SectionPage page) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.ShowPage (MonoDevelop.Ide.Extensions.OptionsDialogSection section) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.OnSelectionChanged (System.Object s, System.EventArgs a) [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0 
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0 
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0 
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0 
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0 
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0 
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0 
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0 

我必须在 monodevelop 设置中的某处指定语言吗？这是口头语言还是编程语言？

Answer 1

我可以通过升级到 Mono 5.10 来解决这个问题

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF

echo "deb http://download.mono-project.com/repo/ubuntu trusty main" | sudo tee /etc/apt/sources.list.d/mono-official.list

sudo apt-get update

sudo apt-get install mono-devel