update :: alpha channel :: mono and msbuild new issue

Solution: use to the beta channel - beta-stretch
http://www.mono-project.com/download/beta/#download-lin-debian

Issue on the alpha channel:

msbuild /t:clean

Microsoft (R) Build Engine version 15.3.0.0 ( Wed Jul 26 17:40:04 UTC 2017) for Mono
Copyright (C) Microsoft Corporation. All rights reserved.

MSBUILD : error MSB1025: An internal failure occurred while running MSBuild.
System.BadImageFormatException: Could not resolve field token 0x04000304
File name: 'Microsoft.Build'
  at Microsoft.Build.CommandLine.MSBuildApp.BuildProject (System.String projectFile, System.String[] targets, System.String toolsVersion, System.Collections.Generic.Dictionary`2[TKey,TValue] globalProperties, Microsoft.Build.Framework.ILogger[] loggers, Microsoft.Build.Framework.LoggerVerbosity verbosity, Microsoft.Build.CommandLine.DistributedLoggerRecord[] distributedLoggerRecords, System.Int32 cpuCount, System.Boolean enableNodeReuse, System.IO.TextWriter preprocessWriter, System.Boolean debugger, System.Boolean detailedSummary, System.Collections.Generic.ISet`1[T] warningsAsErrors, System.Collections.Generic.ISet`1[T] warningsAsMessages) [0x004b7] in <09b0c4ef186c4daa84c1e4c3bb7b9b37>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Execute (System.String commandLine) [0x00169] in <09b0c4ef186c4daa84c1e4c3bb7b9b37>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.BadImageFormatException: Could not resolve field token 0x04000304
File name: 'Microsoft.Build'
  at Microsoft.Build.CommandLine.MSBuildApp.BuildProject (System.String projectFile, System.String[] targets, System.String toolsVersion, System.Collections.Generic.Dictionary`2[TKey,TValue] globalProperties, Microsoft.Build.Framework.ILogger[] loggers, Microsoft.Build.Framework.LoggerVerbosity verbosity, Microsoft.Build.CommandLine.DistributedLoggerRecord[] distributedLoggerRecords, System.Int32 cpuCount, System.Boolean enableNodeReuse, System.IO.TextWriter preprocessWriter, System.Boolean debugger, System.Boolean detailedSummary, System.Collections.Generic.ISet`1[T] warningsAsErrors, System.Collections.Generic.ISet`1[T] warningsAsMessages) [0x004b7] in <09b0c4ef186c4daa84c1e4c3bb7b9b37>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Execute (System.String commandLine) [0x003d3] in <09b0c4ef186c4daa84c1e4c3bb7b9b37>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Main () [0x00028] in <09b0c4ef186c4daa84c1e4c3bb7b9b37>:0