Fornax crashes on build

[oluwandabira]

Describe the bug
Fornax crashes when attempting to build a project with error:

An unexpected error happend: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.Collections.Generic.KeyNotFoundException: An index satisfying the predicate was not found in the collection.
   at Microsoft.FSharp.Collections.SeqModule.Find[T](FSharpFunc`2 predicate, IEnumerable`1 source) in F:\workspace\_work\1\s\src\fsharp\FSharp.Core\seq.fs:line 677
   at FSI_0016.Post.generate'(SiteContents ctx, String page)
   at lambda_method17(Closure , Unit , SiteContents , String , String )
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Generator.EvaluatorHelpers.helper@56(Object next, FSharpList`1 args) in repos/Fornax/src/Fornax/Generator.fs:line 66
   at Generator.EvaluatorHelpers.invokeFunction(Object f, IEnumerable`1 args) in repos/Fornax/src/Fornax/Generator.fs:line 70
   at [email protected](Object generator) in repos/Fornax/src/Fornax/Generator.fs:line 195
   at System.Runtime.CompilerServices.RuntimeHelpers.DispatchTailCalls(IntPtr callersRetAddrSlot, IntPtr callTarget, IntPtr retVal)
   at Generator.GeneratorEvaluator.evaluate(FsiEvaluationSession fsi, SiteContents siteContent, String generatorPath, String projectRoot, String page) in repos/Fornax/src/Fornax/Generator.fs:line 190
   at Generator.generate(FsiEvaluationSession fsi, Config cfg, SiteContents siteContent, String projectRoot, String page) in repos/Fornax/src/Fornax/Generator.fs:line 333
   at Generator.action@1-3(String projectRoot, FsiEvaluationSession fsi, Config config, SiteContents sc, String filePath) in repos/Fornax/src/Fornax/Generator.fs:line 496
   at Generator.generateFolder(String projectRoot, Boolean isWatch) in repos/Fornax/src/Fornax/Generator.fs:line 495
   at Fornax.main$cont@185(ArgumentParser`1 parser, FSharpList`1 results, Unit unitVar) in repos/Fornax/src/Fornax/Fornax.fs:line 213

To Reproduce
Steps to reproduce the behaviour:

1. Clone the Fornax repo
2. Apply the change described in Support .NET SDK 5.0.202 and later #82
3. Build the repo (dotnet tool restore, dotnet fake build, dotnet fake build -t Test)
4. Create a new fornax project (fornax new)
5. Attempt to build the project (fornax build)

Expected behaviour
Fornax builds the site.

Environment (please complete the following information):

• OS: Ubuntu 20.04.2 LTS
• Ionide version: 5.5.5
• VSCode version: 1.56.1
• dotnet SDK version: 5.0.203
• mono / .Net Framework version:

[rdipardo]

Hey @oluwandabira, and others who might come across this:
the underlying problem with file filtering has been patched: https://github.com/rdipardo/Fornax/commit/95e0361a270cd6ef3a65793afb1a7a3335684245
Let me know if it works for you

[oluwandabira]

Tested it and I still get the same error.

[oluwandabira]

So the underlying issue still seems to be with ignored file paths?

[rdipardo]

So the underlying issue still seems to be with ignored file paths?

So I thought, but not any more.

fornax build should now be fixed: e681704

fornax watch is broken, because an empty instance of SiteContents is passed to the generator after a file event

---

I see there's no answer yet to #87, but I wouldn't expect the Generator to pick up this kind of error; it's only watching for the
FornaxGeneratorException type:

Fornax/src/Fornax/Fornax.fs

Lines 216 to 221 in 5902c57

	| FornaxGeneratorException message ->
	Console.WriteLine message
	1
	| exn ->
	printfn "An unexpected error happend: %O" exn
	1

Exceptions throw by generator scripts are emitted by FSI and not handled as far as I know.