multiemit on net8 hosted

Author: goswinr

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.31.0] - 2025-12-19
+### Fixed
+- Show error line numbers for exceptions in hosted net8 context by using multiemit
+
 ## [0.30.1] - 2025-12-19
 ### Changed
 - net472, net8, net9 nuget with suffix, net10 nuget without suffix
@@ -154,7 +158,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - first public release
 
-[Unreleased]: https://github.com/goswinr/Fesh/compare/0.30.1...HEAD
+[Unreleased]: https://github.com/goswinr/Fesh/compare/0.31.0...HEAD
+[0.31.0]: https://github.com/goswinr/Fesh/compare/0.30.1...0.31.0
 [0.30.1]: https://github.com/goswinr/Fesh/compare/0.29.3...0.30.1
 [0.29.3]: https://github.com/goswinr/Fesh/compare/0.29.2...0.29.3
 [0.29.2]: https://github.com/goswinr/Fesh/compare/0.29.0...0.29.2

Src/Config/FsiArguments.fs

@@ -11,11 +11,20 @@ type FsiArguments   ( runContext:RunContext) =
     let writer = SaveReadWriter(filePath0, IFeshLog.printError)
 
     let defaultArgs =
-        if runContext.IsHosted then // dec 2024, F# 9, on net48 hosted in Rhino --multiemit- is needed to enable multiple evaluations, line numbers for errors don't work though.
-            [| "first arg must be there but is ignored" ; "--langversion:preview"  ; "--exec"; "--debug+"; "--debug:full" ;"--optimize+" ; "--gui+" ; "--nologo"; "--multiemit-"|]
-        else // Standalone for net48 too --multiemit is always there on netCore
-            [| "first arg must be there but is ignored" ; "--langversion:preview"  ; "--exec"; "--debug+"; "--debug:full" ;"--optimize+" ; "--gui+" ; "--nologo"; "--multiemit+" |]
-
+        [|
+        "first arg ignored"
+        "--langversion:preview"
+        "--exec"
+        "--debug+"
+        "--debug:full"
+        "--optimize+"
+        "--gui+"
+        "--nologo"
+        if runContext.IsHosted && not runContext.IsRunningOnDotNetCore then // dec 2024, F# 9, on net48 hosted in Rhino --multiemit- is needed to enable multiple evaluations, line numbers for errors don't work though.
+            "--multiemit-"
+        else
+            "--multiemit+" // to see line numbers in error messages
+        |]
 
     // Standalone with "--multiemit" to have line numbers in error messages see https://github.com/dotnet/fsharp/discussions/13293
     // Hosted without "--multiemit", error line numbers don't work there anyway, and in addition accessing previously emitted assemblies might fail with a TypeLoadException.