Fake fails with unhelpful error if %temp% does not exist

[0x53A]

Repro:

set TMP=c:\doesnotexist
set TEMP=c:\doesnotexist
fake.exe ...

Actual:

Build failed.
Error:
The directory name is invalid.

-------------------
 FAKE usage
-------------------

    fake.exe [<scriptPath>] [<targetName>] [options]

    scriptPath: Optional.  Path to your FAKE build script.  If not specified, FAKE will use the first .fsx file in the working directory and fail if none exists.

    targetName: Optional.  Name of the target you wish to run.  This will override the target you specifed to run in the build script.
                           When targetName is equal --listTargets or -lt FAKE will list the targets with their dependencies.

    Options:

Expected:

Either it works, or it prints exactly what directory is invalid. (%temp% in this case).

I think this is a regression to some older version, but not 100% sure.

ToDo:

I propose to just Directory.Create it, and if that also fails to write a nice detailed error message.

This cost me about a day, because my build script failed when executed during the automated serverbuild (which redirects temp), but succeeded, when I just copy-pasted the exact invokation into a new cmd window.

[0x53A]

 	mscorlib.dll!System.IO.__Error.WinIOError(int errorCode, string maybeFullPath)	Unknown	Symbols loaded.
 	mscorlib.dll!System.IO.__Error.WinIOError()	Unknown	Symbols loaded.
 	mscorlib.dll!System.IO.Path.InternalGetTempFileName(bool checkHost)	Unknown	Symbols loaded.
 	mscorlib.dll!System.IO.Path.GetTempFileName()	Unknown	Symbols loaded.
>	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.FSharpAssemblyHelper.getCheckerArguments(string frameworkVersion, System.Collections.Generic.IEnumerable<string> defaultReferences, Microsoft.FSharp.Core.FSharpOption<string> fsCoreLib, System.Collections.Generic.IEnumerable<string> dllFiles, System.Collections.Generic.IEnumerable<string> libDirs, System.Collections.Generic.IEnumerable<string> otherFlags) Line 178	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.FSharpAssemblyHelper.getProjectReferences(string frameworkVersion, Microsoft.FSharp.Core.FSharpOption<System.Collections.Generic.IEnumerable<string>> otherFlags, Microsoft.FSharp.Core.FSharpOption<System.Collections.Generic.IEnumerable<string>> libDirs, System.Collections.Generic.IEnumerable<string> dllFiles) Line 270	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.FSharpAssemblyHelper.getProjectReferencesSimple(string frameworkVersion, System.Collections.Generic.IEnumerable<string> dllFiles) Line 303	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.FSharpAssemblyHelper.getProjectReferenceFromFile(string frameworkVersion, string dllFile) Line 307	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.FSharpAssembly.FromAssembly.Static(System.Reflection.Assembly assembly) Line 367	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.TypeNameHelper.getFSharpTypeName(System.Type t) Line 385	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.Type.get_FSharpName(System.Type value) Line 400	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.Type.get_FSharpFullName(System.Type value) Line 402	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.CompilerServiceExtensions.Type.get_FSharpFullNameWithTypeArgs(System.Type value) Line 427	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.Extensions.IFsiSession.Let<object>(Yaaf.FSharp.Scripting.IFsiSession x, string varName, object obj) Line 719	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.Helper.getSession(object fsi, Yaaf.FSharp.Scripting.FsiOptions options, bool reportGlobal, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> liveOut, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> liveOutFsi, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> liveErr, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> liveErrFsi, bool preventStdOut) Line 1345	F#	Symbols loaded.
 	FakeLib.dll!Yaaf.FSharp.Scripting.ScriptHost.Create(Yaaf.FSharp.Scripting.FsiOptions opts, Microsoft.FSharp.Core.FSharpOption<object> fsiObj, Microsoft.FSharp.Core.FSharpOption<bool> reportGlobal, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> outWriter, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> fsiOutWriter, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> errWriter, Microsoft.FSharp.Core.FSharpOption<System.IO.TextWriter> fsiErrWriter, Microsoft.FSharp.Core.FSharpOption<bool> preventStdOut) Line 1493	F#	Symbols loaded.
 	FakeLib.dll!Fake.FSIHelper.runScriptUncached(bool useCache, System.Collections.Generic.IEnumerable<string> fsiOptions, bool printDetails, Fake.FSIHelper.CacheInfo cacheInfo, System.IO.TextWriter out, System.IO.TextWriter err) Line 515	F#	Symbols loaded.
 	FakeLib.dll!Fake.FSIHelper.runFAKEScriptWithFsiArgsAndRedirectMessages(bool printDetails, Fake.FSIHelper.FsiArgs _arg1, System.Collections.Generic.IEnumerable<System.Tuple<string, string>> env, Microsoft.FSharp.Core.FSharpFunc<string, Microsoft.FSharp.Core.Unit> onErrMsg, Microsoft.FSharp.Core.FSharpFunc<string, Microsoft.FSharp.Core.Unit> onOutMsg, bool useCache) Line 608	F#	Symbols loaded.
 	FakeLib.dll!Fake.FSIHelper.runBuildScriptWithFsiArgsAt(bool printDetails, Fake.FSIHelper.FsiArgs _arg1, System.Collections.Generic.IEnumerable<System.Tuple<string, string>> env, bool useCache) Line 634	F#	Symbols loaded.
 	FAKE.exe!<StartupCode$FAKE>.$Program.main@() Line 122	F#	Symbols loaded.

[matthid]

Did you try with verbose mode?
Did you try with fake 5?

[0x53A]

no and no by Fake5 you mean the new modular one? I've used the fake.nupkg from #1703 which has a version 5.0-betaX.

[matthid]

no and no by Fake5 you mean the new modular one?

Yes.

[matthid]

It seems like fake5 has no problems with this.
So it is an interesting corner case for fake 4 and will be tracked in matthid/Yaaf.FSharp.Scripting#9
But it probably not be hotfixed in fake 4.