NullReferenceException in ProjectCracker

[haf]

Steps:

1. Install mono 5.2 from their clickety-click installer
2. Ensure PATH contains /Library/Frameworks/Mono.framework/Versions/Current/Commands – if you manage your own PATH.
3. forge new project
4. suave
5. .
6. Repro
7. ./build.sh
8. open folder in latest ionide, with latest ionide-fsharp with debugging enabled in the user settings and F#'s "cache" cleared

[17:32:11 DEBUG] RES (077) <- {project} in 25 ms: Kind={"project"}
Data={"Project":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fsproj","Files":[],"Output":"null","References":["/Library/Frameworks/Mono.framework/Versions/5.2.0/lib/mono/4.5/FSharp.Core.dll"],"Logs":{"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fsproj":"Microsoft.Build.Exceptions.InvalidProjectFileException: /Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fsproj: Object reference not set to an instance of an object\n  at Microsoft.FSharp.Compiler.SourceCodeServices.ProjectCrackerTool.ProjectCrackerTool+FSharpProjectFileInfo..ctor (System.String fsprojFileName, Microsoft.FSharp.Core.FSharpOption`1[T] properties, Microsoft.FSharp.Core.FSharpOption`1[T] enableLogging) [0x00129] in <599ca64506d737baa745038345a69c59>:0 \n  at Microsoft.FSharp.Compiler.SourceCodeServices.ProjectCrackerTool.ProjectCrackerTool.getOptions@387 (System.Boolean enableLogging, Microsoft.FSharp.Collections.FSharpList`1[T] properties, System.String file) [0x0000f] in <599ca64506d737baa745038345a69c59>:0 \n  at Microsoft.FSharp.Compiler.SourceCodeServices.ProjectCrackerTool.ProjectCrackerTool.getOptions (System.String file, System.Boolean enableLogging, Microsoft.FSharp.Collections.FSharpList`1[T] properties) [0x00005] in <599ca64506d737baa745038345a69c59>:0 \n  at Microsoft.FSharp.Compiler.SourceCodeServices.ProjectCrackerTool.ProjectCrackerTool.crackOpen (System.String[] argv) [0x000cc] in <599ca64506d737baa745038345a69c59>:0 "},"OutputType":"exe","Info":{"SdkType":"verbose","Data":{}},"AdditionalInfo":{}}
[17:32:11 DEBUG] REQ (078) -> {parse}, File = "~/Repro/Repro.fs"
Data={"FileName":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fs","IsAsync":true,"Lines":["module MyWebApi.Program","","open Suave","open Suave.Successful","","[<EntryPoint>]","let main argv =","  startWebServer defaultConfig (OK \"Hello World!\")","  0"],"Version":23}
[17:32:11 DEBUG] RES (078) <- {parse} in 27 ms: Kind={"errors"}
Data={"File":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fs","Errors":[{"FileName":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fs","StartLine":3,"EndLine":3,"StartColumn":6,"EndColumn":11,"Severity":"Error","Message":"The namespace or module 'Suave' is not defined.","Subcategory":"typecheck"},{"FileName":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fs","StartLine":4,"EndLine":4,"StartColumn":6,"EndColumn":11,"Severity":"Error","Message":"The namespace or module 'Suave' is not defined.","Subcategory":"typecheck"},{"FileName":"/Users/h/dev/haf/_scratch/paket-repro/Repro/Repro.fs","StartLine":8,"EndLine":8,"StartColumn":3,"EndColumn":17,"Severity":"Error","Message":"The value or constructor 'startWebServer' is not defined.","Subcategory":"typecheck"}]}

Possibly related fsprojects/Paket#2616 dotnet/core#862 ionide/ionide-vscode-fsharp#514 ?

[Krzysztof-Cieslak]

Maybe related: ionide/ionide-vscode-fsharp#511

[enricosada]

added ionide/FsAutoComplete#203 to make sure FSAC error out the project request, if project cracker fails somehow.

[haf]

• I don't think ionide doesn't work after latest update ionide/ionide-vscode-fsharp#511 is related, because I've cleaned out the cache.
• It only seem to happen when .Net Core NETLibrary.Standard.targets in included.
• It's related to the issue here Nullref in .targets file fsprojects/Paket#2616 (comment) but Enrico/@matthid said that's the expected behaviour – that NETStandard DLLs are imported for non-.Net Core compiliations, because it's about API surface area and not compilation artifacts. (as far as I understood it)
• Perhaps when .Net Core 2.0's NetStandard.Library targets-file breaks xbuild dotnet/core#862 and subsequently Workaround xbuild dotnet/standard#478 are pushed, it will affect ProjectCracker or FSAutoComplete in a manner that makes it break less.

[dsyme]

My understanding is that this is fixed in master via #812 - @vasily-kirichenko please reopen if that's not the case