Cannot find the specified file error when loading file from generated solution

### Description
After using Bolero template command to create a new project opening the Main.fs results in a message about the file not being a part of the project.

```/data/projects/fsharp/SignUp/src/SignUp.Client/Main.fs is not part of the loaded projects```

### Repro steps
Install dotnet version 3.0.0.100 via linux install script. (Make sure dotnet is on your path.)
Install Bolero template
```dotnet new -i Bolero.Templates```
Create new project
```dotnet new bolero-app -o MyApp```
Please provide the steps required to reproduce the problem

1. Step A
Navigate to Main.fs

### Expected behavior
File should be recognized as part of project.

### Actual behavior

Main.fs is not recognized as part of the solution and no type hint functionality works as expected.

### Debug output
``` 17:14:10.584853: project "/data/projects/fsharp/SignUp/src/SignUp.Client/SignUp.Client.fsproj" verbose
17:14:10.593027: {"Kind":"error","Data":{"Code":101,"Message":"ApplicationName='dotnet', CommandLine='msbuild /data/projects/fsharp/SignUp/src/SignUp.Client/SignUp.Client.fsproj /p:SkipCompilerExecution=true /p:ProvideCommandLineArgs=true /p:CopyBuildOutputToOutputDirectory=false /p:UseCommonOutputDirectory=true /t:_Inspect_FscArgs /p:_Inspect_FscArgs_OutFile=/tmp/tmp4ad706e.tmp.FscArgs.txt /p:DesignTimeBuild=true /t:_Inspect_GetResolvedProjectReferences /p:_Inspect_GetResolvedProjectReferences_OutFile=/tmp/tmp376767bb.tmp.GetResolvedProjectReferences.txt /t:_Inspect_GetProperties /p:_Inspect_GetProperties_OutFile=/tmp/tmp5a174522.tmp.GetProperties.txt /p:CustomAfterMicrosoftCommonTargets=/tmp/tmp168ff7a2.tmp.proj-info.hook.targets /p:CustomAfterMicrosoftCommonCrossTargetingTargets=/tmp/tmp168ff7a2.tmp.proj-info.hook.targets /nologo /verbosity:quiet', CurrentDirectory='/data/projects/fsharp/SignUp/src/SignUp.Client', Native error= Cannot find the specified file","AdditionalData":{"Project":"/data/projects/fsharp/SignUp/src/SignUp.Client/SignUp.Client.fsproj"}}}
17:14:10.593403: Received ’error’ message of length 2
17:27:00.005682: project "/data/projects/fsharp/SignUp/src/SignUp.Server/SignUp.Server.fsproj" verbose
17:27:00.042084: {"Kind":"error","Data":{"Code":101,"Message":"ApplicationName='dotnet', CommandLine='msbuild /data/projects/fsharp/SignUp/src/SignUp.Server/SignUp.Server.fsproj /p:SkipCompilerExecution=true /p:ProvideCommandLineArgs=true /p:CopyBuildOutputToOutputDirectory=false /p:UseCommonOutputDirectory=true /t:_Inspect_FscArgs /p:_Inspect_FscArgs_OutFile=/tmp/tmp575416f1.tmp.FscArgs.txt /p:DesignTimeBuild=true /t:_Inspect_GetResolvedProjectReferences /p:_Inspect_GetResolvedProjectReferences_OutFile=/tmp/tmp70876e64.tmp.GetResolvedProjectReferences.txt /t:_Inspect_GetProperties /p:_Inspect_GetProperties_OutFile=/tmp/tmpda770b0.tmp.GetProperties.txt /p:CustomAfterMicrosoftCommonTargets=/tmp/tmp508d0280.tmp.proj-info.hook.targets /p:CustomAfterMicrosoftCommonCrossTargetingTargets=/tmp/tmp508d0280.tmp.proj-info.hook.targets /nologo /verbosity:quiet', CurrentDirectory='/data/projects/fsharp/SignUp/src/SignUp.Server', Native error= Cannot find the specified file","AdditionalData":{"Project":"/data/projects/fsharp/SignUp/src/SignUp.Server/SignUp.Server.fsproj"}}}
17:27:00.042306: Received ’error’ message of length 2
```

### Known workarounds

None known at this time.

### Related information

* Operating system
Manjaro 18.1.0

* Emacs version
GNU Emacs 26.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.10)
of 2019-08-29
* .NET Runtime, CoreCLR or Mono Version
dotnet core 3.0.0.100

Reproduce the issue with the Bolero template commands and inspect the generated SignUp.Client.fsproj and SignUp.Server.fsproj from the debug output. Start by checking why the design-time msbuild invocation cannot find dotnet on the reported Manjaro setup. Done means Main.fs is recognized as part of the loaded project and type hints work.

Written by the indexing model from the issue text.