Variables in supplied ".target" file seems undefined leading to compilation error

Description

I have the following issue :

2>------ Rebuild All started: Project: <project>, Configuration: Release x64 ------
2>		"\"  -o "Lexer.fs" --unicode Lexer.fsl
2>		'"\"' n'est pas reconnu en tant que commande interne
2>		ou externe, un programme exécutable ou un fichier de commandes.
2><projectdir>\packages\FsLexYacc.10.2.0\build\fsyacc\netcoreapp3.1\FsLexYacc.targets(36,3): error MSB3073: The command ""\"  -o "Lexer.fs" --unicode Lexer.fsl" exited with code 9009.

(I replaced my project name and directory with <> in the copied text above) (the text in french translate to :“…is not recognized as an internal or external command, executable program, or batch file.”)

For the first part of the command to be “\”, I suspect some variables in the file “FsLexYacc.targets” gets undefined (path and exec I guess), which seems to lead to faulty command.

I had been using the library without any problems up to date, this problem came when I migrated from version 10.0 to 10.2 of FsLexYacc.

The project is built with Visual Studio 2019, and the framework is “.NET Framework 4.6.1”.

Known workarounds

None known.

Related information

• Operating system : Windows
• .NET Runtime : .NET Framework 4.6.1

Thanks in advance !

[lkluc]

It seems it worked correctly when using the provided “dotnet build” command. However my project was still not compiling from Visual Studio interface. I managed to get it work by adding these properties in the “fsproj” file :

  <PropertyGroup>
    <OutputType>Library</OutputType>
    <FsLexToolPath>..\packages\FsLexYacc.10.2.0\build\fslex\netcoreapp3.1</FsLexToolPath>
    <FsYaccToolPath>..\packages\FsLexYacc.10.2.0\build\fsyacc\netcoreapp3.1</FsYaccToolPath>
    <FsLexToolExe>fslex.dll</FsLexToolExe>
    <FsYaccToolExe>fsyacc.dll</FsYaccToolExe>
    <FsLexYaccToolRunner>dotnet </FsLexYaccToolRunner>
  </PropertyGroup>

I believe the NuGet package for 10.2.0 is not working correctly with .NET Standard 2.0 projects, maybe the problems lies in the configuration in the supplied “targets” file? …as if those variables where undefined, or the “targets” files does not get found by the VS build system… ?

[dsyme]

Yes, though it may be failing with hidden diagnostics for whatever reasons. May be try dotnet build -v:d and check logs carefully. If it still fails maybe try to invoke fslex directly from the command line.