[Repo Assist] Add trimming support to runtime Core libraries (closes #1436)

RELEASE_NOTES.md

@@ -8,6 +8,7 @@
 - Make `Http.AppendQueryToUrl` public (closes #1325)
 - Add `PreferOptionals` parameter to `JsonProvider` and `XmlProvider` (defaults to `true` to match existing behavior; set to `false` to use empty string or `NaN` for missing values, like the CsvProvider default) (closes #649)
 - Add `UseSchemaTypeNames` parameter to `XmlProvider`: when `true` and `Schema` is provided, multiple elements sharing the same XSD complex type generate a single F# type (named after the XSD type) instead of separate per-element types (closes #1488)
+- Mark all runtime Core libraries as trimmable (`IsTrimmable=true`); replace reflection-based stack-trace preservation in `Http.fs` with `ExceptionDispatchInfo`, and remove dead Mono-detection code (closes #1436)
 
 ## 8.0.0 - Feb 25 2026
 

src/FSharp.Data.Csv.Core/FSharp.Data.Csv.Core.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="CsvRuntime.fs" />

src/FSharp.Data.Html.Core/FSharp.Data.Html.Core.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
     <DefineConstants>$(DefineConstants);HIDE_REPRESENTATION</DefineConstants>
   </PropertyGroup>
   <ItemGroup>

src/FSharp.Data.Http/FSharp.Data.Http.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Http.fs" />

src/FSharp.Data.Http/Http.fs

@@ -11,8 +11,8 @@ open System.Net
 open System.Text
 open System.Text.RegularExpressions
 open System.Threading
-open System.Reflection
 open System.Runtime.CompilerServices
+open System.Runtime.ExceptionServices
 open System.Runtime.InteropServices
 
 /// The method to use in an HTTP request
@@ -1607,12 +1607,6 @@ module internal HttpHelpers =
             source.Dispose()
         }
 
-    let runningOnMono =
-        try
-            not (isNull (System.Type.GetType "Mono.Runtime"))
-        with e ->
-            false
-
     let writeBody (req: HttpWebRequest) (data: Stream) =
         async {
             if data.CanSeek then
@@ -1624,16 +1618,8 @@ module internal HttpHelpers =
         }
 
     let reraisePreserveStackTrace (e: Exception) =
-        try
-            let remoteStackTraceString =
-                typeof<exn>.GetField("_remoteStackTraceString", BindingFlags.Instance ||| BindingFlags.NonPublic)
-
-            if not (isNull remoteStackTraceString) then
-                remoteStackTraceString.SetValue(e, e.StackTrace + Environment.NewLine)
-        with _ ->
-            ()
-
-        raise e
+        ExceptionDispatchInfo.Capture(e).Throw()
+        raise e // unreachable; satisfies type checker
 
     let augmentWebExceptionsWithDetails f =
         async {

src/FSharp.Data.Json.Core/FSharp.Data.Json.Core.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="JsonValue.fs" />

src/FSharp.Data.Runtime.Utilities/FSharp.Data.Runtime.Utilities.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="PublicApi.fs" />

src/FSharp.Data.WorldBank.Core/FSharp.Data.WorldBank.Core.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="WorldBankRuntime.fs" />

src/FSharp.Data.Xml.Core/FSharp.Data.Xml.Core.fsproj

@@ -9,6 +9,7 @@
     <PackageIcon>logo.png</PackageIcon>
     <!-- always have tailcalls on for design time compiler add-in to allow repo to compile in DEBUG, see https://github.com/fsprojects/FSharp.Data/issues/1410 -->
     <Tailcalls>true</Tailcalls>
+    <IsTrimmable>true</IsTrimmable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="XmlRuntime.fs" />