AGiorgetti · Oct 15, 2026 · Oct 15, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -328,6 +328,19 @@ jobs:
             throw 'Packages contain Roslyn runtime assets.'
           }
 
+      - name: Validate package symbols
+        shell: pwsh
+        run: |
+          $version = '${{ steps.gitversion.outputs.semver }}'
+          $feed = (Resolve-Path '${{ env.PACKAGE_OUTPUT }}').Path
+          $symbolPairs = @()
+          foreach ($packageId in @('Mammoth.LiteMapper.Abstractions', 'Mammoth.LiteMapper.Generator', 'Mammoth.LiteMapper')) {
+            $symbolPairs += Join-Path $feed "$packageId.$version.nupkg"
+            $symbolPairs += Join-Path $feed "$packageId.$version.snupkg"
+          }
+          dotnet run --project tools/Mammoth.LiteMapper.PackageValidation/Mammoth.LiteMapper.PackageValidation.csproj -c Release --no-restore -- @symbolPairs
+          if ($LASTEXITCODE -ne 0) { throw "Package symbol validation failed with exit code $LASTEXITCODE." }
+
       - name: Validate final package consumers
         shell: pwsh
         run: |

diff --git a/DECISIONS.md b/DECISIONS.md
@@ -1,5 +1,14 @@
 # Mammoth.LiteMapper Decision Log
 
+## Generator symbol package layout (2026-10-15)
+
+- Contract: specification sections 4.1, 22.19 and 24.6 require analyzer isolation, valid shipping packages and portable reproducible symbols. No public API or mapping semantic change is needed.
+- Cause: the published 4.0.1 generator DLL lives under analyzers/dotnet/cs, while automatic debug-output packing placed its matching PDB under lib/netstandard2.0. Removing BuiltProjectOutputGroupOutput did not remove the separate debug-symbol output group.
+- Packing: disable automatic generator build-output packing and explicitly pack its DLL and PDB at the analyzer path. The PDB is also included beside the analyzer DLL in the regular generator package; neither becomes a runtime lib/ref asset.
+- Validation: use one standalone .NET validator in package tests, release CI before artifact promotion, and the manual publication script, including -SkipValidation and dry runs. Check metadata, path pairing, portable format, PE/PDB association and the compiler checksum with the PDB ID zeroed. Determinism and checksum manifests remain required but do not prove symbol validity.
+- Coverage follows NuGet's supplied-PDB-to-assembly rule; it does not require a duplicate PDB for every packaged DLL. Shipping tests require the Abstractions and primary runtime PDBs plus the standalone generator's analyzer PDB. The primary package's duplicated analyzer DLL does not need a second copy of those globally indexed symbols.
+- Recovery: the original release PDB matches the immutable 4.0.1 DLL. A separately prepared snupkg changes only that entry's path and can be submitted independently at the existing ID/version. Preparation and PR creation do not authorize publication. The PR targets develop because 4.0.1 is published and its release branch was removed.
+
 ## Issues #55 and #56: legal target accessors and required construction (2026-10-15)
 
 - Contract: specification sections 6.4, 9.1, 10.4-10.5, 14.1, 16.1 and 20.1-20.3 already define legal target assignment and mandatory required-member diagnostics. No normative change or new API is needed.

diff --git a/IMPLEMENTATION_PLAN.md b/IMPLEMENTATION_PLAN.md
@@ -1,5 +1,13 @@
 # Mammoth.LiteMapper Implementation Plan
 
+## Generator symbol package repair (2026-10-15)
+
+- Scope: user-authorized packaging maintenance on an isolated branch from develop after the 4.0.1 release. Prepare corrected 4.0.1 symbols separately, then open a draft PR against develop; the release branch has been removed. This is direct maintenance, not a claimed tracker item.
+- Test-first: validate every shipping nupkg/snupkg pair, reproducing the generator PDB path mismatch before changing its pack configuration. Reject mismatched PE/PDB identity, compiler checksum, nonportable symbols, and inconsistent package metadata.
+- Implementation: disable automatic generator build-output packing and explicitly place its DLL and portable PDB together under analyzers/dotnet/cs. Reuse one archive/identity/checksum validator in tests, release CI and the manual publishing script before publication.
+- Validation: focused regressions, full correctness and packaging coverage excluding local benchmark-launching tests, independent review, and terminal exact-head Windows/Linux and Roslyn CI. Preserve existing CI gates, skill content, and performance tests.
+- Boundary: corrected symbols are delivered for a separate human upload. No NuGet push, package replacement/unlisting, tag, merge, credential changes, machine settings, or local timing benchmarks are authorized.
+
 ## Release 4.0.1 corrections: issues #55 and #56 (2026-10-15)
 
 - Scope: user-authorized combined repair on an isolated branch from release/4.0.1 at d7d8c3bbc578470ddb9403c2a9064b96d8d87b25, with a draft PR back to that release branch.

diff --git a/Mammoth.LiteMapper.sln b/Mammoth.LiteMapper.sln
@@ -35,6 +35,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mammoth.LiteMapper.Benchmar
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mammoth.LiteMapper.ProcessFixture", "tests\Mammoth.LiteMapper.Packaging.Tests\ProcessFixture\Mammoth.LiteMapper.ProcessFixture.csproj", "{A8B5221B-4D45-4E98-83B9-C4F5A0FD6E29}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tools", "tools", "{E63B4D72-2B11-4B36-99B4-489B586E2321}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Mammoth.LiteMapper.PackageValidation", "tools\Mammoth.LiteMapper.PackageValidation\Mammoth.LiteMapper.PackageValidation.csproj", "{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -189,6 +193,18 @@ Global
 		{A8B5221B-4D45-4E98-83B9-C4F5A0FD6E29}.Release|x64.Build.0 = Release|Any CPU
 		{A8B5221B-4D45-4E98-83B9-C4F5A0FD6E29}.Release|x86.ActiveCfg = Release|Any CPU
 		{A8B5221B-4D45-4E98-83B9-C4F5A0FD6E29}.Release|x86.Build.0 = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|x64.Build.0 = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Debug|x86.Build.0 = Debug|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|x64.ActiveCfg = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|x64.Build.0 = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|x86.ActiveCfg = Release|Any CPU
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -206,5 +222,6 @@ Global
 		{77429349-3F3A-4DDA-B18A-D148612D07DD} = {5D20AA90-6969-D8BD-9DCD-8634F4692FDA}
 		{9FAC9778-94D0-4ADC-B2FE-6DBC5715A38E} = {66320409-64EC-F7C5-3DEF-65E7510DAAD1}
 		{A8B5221B-4D45-4E98-83B9-C4F5A0FD6E29} = {0AB3BF05-4346-4AA6-1389-037BE0695223}
+		{C5F34DF8-E046-4D3A-B7F7-47E54D56C3F0} = {E63B4D72-2B11-4B36-99B4-489B586E2321}
 	EndGlobalSection
 EndGlobal
diff --git a/Mammoth.LiteMapper.slnx b/Mammoth.LiteMapper.slnx
@@ -24,4 +24,7 @@
     <Project Path="tests/Mammoth.LiteMapper.Packaging.Tests/ProcessFixture/Mammoth.LiteMapper.ProcessFixture.csproj" />
     <Project Path="tests/Mammoth.LiteMapper.Runtime.Tests/Mammoth.LiteMapper.Runtime.Tests.csproj" />
   </Folder>
+  <Folder Name="/tools/">
+    <Project Path="tools/Mammoth.LiteMapper.PackageValidation/Mammoth.LiteMapper.PackageValidation.csproj" />
+  </Folder>
 </Solution>
diff --git a/STATUS.md b/STATUS.md
@@ -1,5 +1,14 @@
 # Mammoth.LiteMapper Status
 
+## Generator symbol packaging checkpoint (2026-10-15)
+
+- Scope: direct user-authorized maintenance from develop after 4.0.1 publication. The old release branch is absent. The isolated fix branch targets develop and stops at draft PR/human review.
+- Reproduction: the retained tag-run generator snupkg has its PDB under lib/netstandard2.0 while the published DLL is under analyzers/dotnet/cs. All six release-artifact hashes were verified. Published nupkg payloads match the retained release packages, and the generator PDB matches the published DLL's portable identity and compiler checksum.
+- Red-first: the shipping-pair regression failed on that exact orphan path while ten fixture checks passed. Three publication-gate tests failed before script integration. After the fix, the focused symbol/gate group passed 14 tests and the release/native safeguard group passed 60 tests. Additional no-PDB and partial-symbol controls document NuGet's supplied-PDB validation direction.
+- Implementation: explicit generator analyzer DLL/PDB packing replaces the build-output-removal target. The shared nonshipping validator checks package metadata, archive paths, portability, PE/PDB association and compiler checksum. Release CI and the manual publishing script validate every shipping pair before promotion or push, including skip-validation and dry-run paths.
+- Validation: Release solution build passes with no compiler errors; two existing generator-test dependency audit warnings remain. Local generator correctness 1,083, runtime five and integration one pass, with allocation measurements and the benchmark launcher excluded from local execution. Package-suite results and terminal exact-head Windows/Linux/Roslyn CI evidence are recorded in the draft PR. Independent read-only review found no remaining actionable issue.
+- Recovery boundary: corrected 4.0.1 symbols preserve every entry's payload and change only the generator PDB archive path. They passed validation against the actual published nupkg and were delivered separately for human re-upload. No NuGet upload, unlist, tag, merge, credential/system change, skill/performance-test edit or local timing benchmark was performed.
+
 ## Release 4.0.1 issues #55 and #56 (2026-10-15)
 
 - Base: remote release/4.0.1 independently verified unchanged at d7d8c3bbc578470ddb9403c2a9064b96d8d87b25. Work uses the isolated feature/4.0.1-mapping-corrections branch; exactly two nonduplicate bug issues were created and claimed through AgentStack.

diff --git a/docs/USAGE.md b/docs/USAGE.md
@@ -1005,6 +1005,8 @@ Windows and Linux are supported. A `netstandard2.0` library runs inside an appli
 
 The primary `Mammoth.LiteMapper` package is the normal install path. `Mammoth.LiteMapper.Generator` is the generator implementation package and is not the normal consumer install route.
 
+The generator DLL is an analyzer asset under `analyzers/dotnet/cs`, outside runtime `lib` and `ref` assets. Portable symbols must match the exact compiled DLL and use the same archive-relative path in the corresponding `.snupkg`, replacing `.dll` with `.pdb`. Symbol-package corrections do not require changing an application's package reference.
+
 ## Analyzer options
 
 The generator recognizes these optional build properties for diagnostics and development. In the consuming project, set each value and export it with `CompilerVisibleProperty` so Roslyn passes it to the generator:

diff --git a/publish-nuget.ps1 b/publish-nuget.ps1
@@ -175,8 +175,21 @@ if ($unexpected.Count -ne 0 -or $missing.Count -ne 0 -or $artifacts.Count -ne $e
     throw "Expected exactly $($expectedArtifacts.Count) versioned package artifacts for $version; missing: $($missing -join ', '); unexpected: $($unexpected.Name -join ', ')."
 }
 
-foreach ($packageId in $packageIds) {
-    $artifactName = "$packageId.$version.nupkg"
+$symbolValidator = 'tools/Mammoth.LiteMapper.PackageValidation/Mammoth.LiteMapper.PackageValidation.csproj'
+if ($SkipValidation) {
+    & dotnet restore $symbolValidator
+    Assert-NativeSuccess 'Restore package symbol validator'
+}
+$symbolPairs = @()
+foreach ($packageId in $packageIds) {
+    $symbolPairs += Join-Path $resolvedOutput "$packageId.$version.nupkg"
+    $symbolPairs += Join-Path $resolvedOutput "$packageId.$version.snupkg"
+}
+& dotnet run --project $symbolValidator -c Release --no-restore -- @symbolPairs
+Assert-NativeSuccess 'Validate package symbols'
+
+foreach ($packageId in $packageIds) {
+    $artifactName = "$packageId.$version.nupkg"
     $artifactPath = Join-Path $resolvedOutput $artifactName
     if ($DryRun) {
         Write-Host "Dry run: would publish $artifactPath to $Source"

diff --git a/src/Mammoth.LiteMapper.Generator/Mammoth.LiteMapper.Generator.csproj b/src/Mammoth.LiteMapper.Generator/Mammoth.LiteMapper.Generator.csproj
@@ -2,6 +2,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <IsPackable>true</IsPackable>
+    <IncludeBuildOutput>false</IncludeBuildOutput>
     <SuppressDependenciesWhenPacking>true</SuppressDependenciesWhenPacking>
     <Description>Source generator package for Mammoth.LiteMapper.</Description>
     <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
@@ -14,11 +15,9 @@
           Pack="true"
           PackagePath="analyzers/dotnet/cs"
           Visible="false" />
+    <None Include="$(OutputPath)$(AssemblyName).pdb"
+          Pack="true"
+          PackagePath="analyzers/dotnet/cs"
+          Visible="false" />
   </ItemGroup>
-
-  <Target Name="ExcludeGeneratorRuntimeAssemblyFromPackage" AfterTargets="BuiltProjectOutputGroup">
-    <ItemGroup>
-      <BuiltProjectOutputGroupOutput Remove="@(BuiltProjectOutputGroupOutput)" />
-    </ItemGroup>
-  </Target>
 </Project>
diff --git a/tests/Mammoth.LiteMapper.Packaging.Tests/Mammoth.LiteMapper.Packaging.Tests.csproj b/tests/Mammoth.LiteMapper.Packaging.Tests/Mammoth.LiteMapper.Packaging.Tests.csproj
@@ -7,6 +7,7 @@
   <ItemGroup>
     <Compile Remove="ProcessFixture\**\*.cs" />
     <ProjectReference Include="ProcessFixture\Mammoth.LiteMapper.ProcessFixture.csproj" />
+    <ProjectReference Include="..\..\tools\Mammoth.LiteMapper.PackageValidation\Mammoth.LiteMapper.PackageValidation.csproj" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" />