msbuild: "internal failure occurred" – EntryPointNotFoundException: CreateProcess

This is an unhandled exception in MSBuild -- PLEASE OPEN A BUG AGAINST THE MSBUILD TEAM.
System.EntryPointNotFoundException: CreateProcess
  at Microsoft.Build.Execution.BuildManager.EndBuild () [0x001f7] in <8e9231c377824a4db813d79e4a419e9a>:0
  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) [0x00445] in <134803388cc84c98a5853ca3c6e7d02f>:0

MSBUILD : error MSB1025: An internal failure occurred while running MSBuild.
System.EntryPointNotFoundException: CreateProcess
  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) [0x00534] in <134803388cc84c98a5853ca3c6e7d02f>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Execute (System.String commandLine) [0x00119] in <134803388cc84c98a5853ca3c6e7d02f>:0
This is an unhandled exception in MSBuild Engine -- PLEASE OPEN A BUG AGAINST THE MSBUILD TEAM.
System.EntryPointNotFoundException: CreateProcess
  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) [0x00534] in <134803388cc84c98a5853ca3c6e7d02f>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Execute (System.String commandLine) [0x00119] in <134803388cc84c98a5853ca3c6e7d02f>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.EntryPointNotFoundException: CreateProcess
  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) [0x00534] in <134803388cc84c98a5853ca3c6e7d02f>:0
  at Microsoft.Build.CommandLine.MSBuildApp.Execute (System.String commandLine) [0x00119] in <134803388cc84c98a5853ca3c6e7d02f>:0

Mono JIT compiler version 4.8.1 (Stable 4.8.1.0/22a39d7 Thu Apr 20 05:31:33 BST 2017)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           normal
	SIGSEGV:       altstack
	Notification:  kqueue
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug
	LLVM:          supported, not enabled.
	GC:            sgen

This happens with the /m switch enabled. Not otherwise.