skuirrels · skuirrels · Jul 25, 2026 · Jul 25, 2026 · Jul 25, 2026 · Jul 25, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -70,6 +70,12 @@ jobs:
         CoverletOutputFormat: lcov
       run: dotnet test --configuration Release --verbosity normal --logger GitHubActions /p:CollectCoverage=true /p:CoverletOutputFormat=lcov /p:BuildType=Full /p:DoesNotReturnAttribute="DoesNotReturnAttribute"
 
+    - name: Trust Coveralls Homebrew tap
+      if: runner.os == 'macOS' && github.event_name != 'schedule'
+      run: |
+        brew tap coverallsapp/coveralls
+        brew trust coverallsapp/coveralls
+
     - name: Upload coverage reports to Coveralls Parallel
       uses: coverallsapp/github-action@v2
       if: github.event_name != 'schedule'

diff --git a/.github/workflows/preview-release.yml b/.github/workflows/preview-release.yml
@@ -12,10 +12,8 @@ jobs:
   publish-fork-package:
     if: >-
       startsWith(github.event.release.tag_name, 'v1.5.') &&
-      ((github.event.release.prerelease == true &&
-        contains(github.event.release.tag_name, '-preview.')) ||
-       (github.event.release.prerelease == false &&
-        !contains(github.event.release.tag_name, '-')))
+      github.event.release.prerelease == false &&
+      !contains(github.event.release.tag_name, '-')
     runs-on: ubuntu-latest
     environment: nuget-preview
 
@@ -32,21 +30,14 @@ jobs:
           version="${{ github.event.release.tag_name }}"
           version="${version#v}"
 
-          if [[ "$version" =~ ^1\.5\.[0-9]+-preview\.[0-9]+$ ]]; then
-            fork_preview=true
-            fork_release=false
-          elif [[ "$version" =~ ^1\.5\.[0-9]+$ ]]; then
-            fork_preview=false
-            fork_release=true
-          else
+          if [[ ! "$version" =~ ^1\.5\.[0-9]+(\.[0-9]+)?$ ]]; then
             echo "Unexpected fork package version: $version" >&2
             exit 1
           fi
 
           {
             echo "PACKAGE_VERSION=$version"
-            echo "FORK_PREVIEW=$fork_preview"
-            echo "FORK_RELEASE=$fork_release"
+            echo "FORK_RELEASE=true"
           } >> "$GITHUB_ENV"
 
       - name: Setup .NET SDK
@@ -65,7 +56,6 @@ jobs:
           /m:1
           /p:BuildType=Full
           /p:CI=false
-          /p:ForkPreview="$FORK_PREVIEW"
           /p:ForkRelease="$FORK_RELEASE"
           /p:Version="$PACKAGE_VERSION"
           /p:PackageVersion="$PACKAGE_VERSION"
@@ -80,7 +70,6 @@ jobs:
           --logger "console;verbosity=quiet"
           /p:BuildType=Full
           /p:CI=false
-          /p:ForkPreview="$FORK_PREVIEW"
           /p:ForkRelease="$FORK_RELEASE"
           /p:DoesNotReturnAttribute=DoesNotReturnAttribute
 
@@ -96,7 +85,6 @@ jobs:
             /m:1
             /p:BuildType=Full
             /p:CI=false
-            /p:ForkPreview="$FORK_PREVIEW"
             /p:ForkRelease="$FORK_RELEASE"
             /p:ForkPack=true
             /p:Version="$PACKAGE_VERSION"
@@ -109,7 +97,6 @@ jobs:
             --source https://api.nuget.org/v3/index.json \
             /p:BuildType=Full \
             /p:CI=false \
-            /p:ForkPreview="$FORK_PREVIEW" \
             /p:ForkRelease="$FORK_RELEASE" \
             /p:ForkPack=true \
             /p:Version="$PACKAGE_VERSION" \

diff --git a/Directory.Build.props b/Directory.Build.props
@@ -21,6 +21,7 @@
 
     <ForkPackageBuild Condition="'$(ForkPreview)' == 'true' OR '$(ForkRelease)' == 'true'">true</ForkPackageBuild>
     <ForkPackagePrefix Condition="'$(ForkPackageBuild)' == 'true' AND '$(ForkPackagePrefix)' == ''">Skuirrels.</ForkPackagePrefix>
+    <DuckDbNativeVersion Condition="'$(DuckDbNativeVersion)' == ''">1.5.5</DuckDbNativeVersion>
     <Product>DuckDB.NET.$(MSBuildProjectName)</Product>
     <PackageId>$(ForkPackagePrefix)DuckDB.NET.$(MSBuildProjectName)</PackageId>
     <PackageTags>DuckDB;ADO.NET;Database;Olap;Embedded</PackageTags>

diff --git a/DuckDB.NET.Benchmarks/PreparedCommandWorkload.cs b/DuckDB.NET.Benchmarks/PreparedCommandWorkload.cs
@@ -9,7 +9,7 @@ internal static class PreparedCommandWorkload
 #if DUCKDB_NET_BASELINE_1_5_3
     private const string ExpectedEngineVersion = "v1.5.3";
 #else
-    private const string ExpectedEngineVersion = "v1.5.4";
+    private const string ExpectedEngineVersion = "v1.5.5";
 #endif
 
     public static DuckDBConnection OpenVerifiedConnection()

diff --git a/DuckDB.NET.Bindings/Bindings.csproj b/DuckDB.NET.Bindings/Bindings.csproj
@@ -3,15 +3,15 @@
   <PropertyGroup>
     <Description>DuckDB Bindings for C#.</Description>
     <PackageReleaseNotes>
-- Updated to DuckDB v1.5.4
+- Updated to DuckDB v$(DuckDbNativeVersion)
     </PackageReleaseNotes>
     <Description Condition="'$(ForkPreview)' == 'true'">Unofficial preview build of the DuckDB native bindings from the skuirrels DuckDB.NET fork.</Description>
     <PackageReleaseNotes Condition="'$(ForkPreview)' == 'true'">Unofficial preview bindings for the consolidated DuckDB.NET performance work, bundling DuckDB v1.5.4.</PackageReleaseNotes>
     <Description Condition="'$(ForkRelease)' == 'true'">Unofficial stable build of the DuckDB native bindings from the skuirrels DuckDB.NET fork.</Description>
-    <PackageReleaseNotes Condition="'$(ForkRelease)' == 'true'">Stable fork bindings for the consolidated DuckDB.NET performance work, bundling DuckDB v1.5.4.</PackageReleaseNotes>
+    <PackageReleaseNotes Condition="'$(ForkRelease)' == 'true'">Stable fork bindings for the consolidated DuckDB.NET performance work, bundling DuckDB v$(DuckDbNativeVersion).</PackageReleaseNotes>
     <RootNamespace>DuckDB.NET.Native</RootNamespace>
     <RuntimeIdentifiers>win-x64;win-arm64;linux-x64;linux-arm64;osx</RuntimeIdentifiers>
-    <DuckDbArtifactRoot Condition=" '$(DuckDbArtifactRoot)' == '' ">https://github.com/duckdb/duckdb/releases/download/v1.5.4</DuckDbArtifactRoot>
+    <DuckDbArtifactRoot Condition=" '$(DuckDbArtifactRoot)' == '' ">https://github.com/duckdb/duckdb/releases/download/v$(DuckDbNativeVersion)</DuckDbArtifactRoot>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>..\keyPair.snk</AssemblyOriginatorKeyFile>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>

diff --git a/DuckDB.NET.Bindings/DownloadNativeLibs.targets b/DuckDB.NET.Bindings/DownloadNativeLibs.targets
@@ -1,47 +1,55 @@
-<Project DefaultTargets="DownloadReleaseNatives;DownloadNightlyNatives">
+<Project DefaultTargets="DownloadNativeLibrary">
 
-  <!-- Release: download lib zip directly -->
-  <Target Name="DownloadReleaseNatives"
-          Condition="!Exists('$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native') AND '$(InnerZipName)' == ''">
+  <Target Name="DownloadNativeLibrary">
     <PropertyGroup>
+      <NativeDirectory>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native</NativeDirectory>
       <NativeZipPath>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native.zip</NativeZipPath>
+      <NativeSourceStampPath>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\source-url.txt</NativeSourceStampPath>
+      <TempExtractPath>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\temp</TempExtractPath>
+    </PropertyGroup>
+    <ReadLinesFromFile File="$(NativeSourceStampPath)"
+                       Condition="Exists('$(NativeSourceStampPath)')">
+      <Output TaskParameter="Lines" ItemName="_CachedNativeSourceUrl" />
+    </ReadLinesFromFile>
+    <PropertyGroup>
+      <NativeCacheIsCurrent Condition="Exists('$(NativeDirectory)') AND '@(_CachedNativeSourceUrl)' == '$(LibUrl)'">true</NativeCacheIsCurrent>
+      <DownloadNative Condition="'$(NativeCacheIsCurrent)' != 'true'">true</DownloadNative>
     </PropertyGroup>
-    <MakeDir Directories="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native" />
+    <RemoveDir Directories="$(NativeDirectory)"
+               Condition="'$(DownloadNative)' == 'true' AND Exists('$(NativeDirectory)')" />
+    <RemoveDir Directories="$(TempExtractPath)"
+               Condition="'$(DownloadNative)' == 'true' AND Exists('$(TempExtractPath)')" />
+    <MakeDir Directories="$(NativeDirectory)"
+             Condition="'$(DownloadNative)' == 'true'" />
     <Delete Files="$(NativeZipPath)"
-            Condition="Exists('$(NativeZipPath)')"
+            Condition="'$(DownloadNative)' == 'true' AND Exists('$(NativeZipPath)')"
             ContinueOnError="true"/>
     <DownloadFile
+            Condition="'$(DownloadNative)' == 'true'"
             DestinationFolder="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)"
             SourceUrl="$(LibUrl)"
             Retries="5"
             RetryDelayMilliseconds="1000"
             DestinationFileName="native.zip"/>
-    <Unzip DestinationFolder="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native"
+    <!-- Release archives contain the native library directly. -->
+    <Unzip Condition="'$(DownloadNative)' == 'true' AND '$(InnerZipName)' == ''"
+           DestinationFolder="$(NativeDirectory)"
            SourceFiles="$(NativeZipPath)"/>
-    <Delete Files="$(NativeZipPath)"/>
-  </Target>
-
-  <!-- Nightly: download outer zip, extract inner lib zip -->
-  <Target Name="DownloadNightlyNatives"
-          Condition="!Exists('$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native') AND '$(InnerZipName)' != ''">
-    <PropertyGroup>
-      <NativeZipPath>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native.zip</NativeZipPath>
-      <TempExtractPath>$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\temp</TempExtractPath>
-    </PropertyGroup>
-    <MakeDir Directories="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native" />
-    <Delete Files="$(NativeZipPath)" Condition="Exists('$(NativeZipPath)')" ContinueOnError="true"/>
-    <DownloadFile
-            DestinationFolder="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)"
-            SourceUrl="$(LibUrl)"
-            Retries="5"
-            RetryDelayMilliseconds="1000"
-            DestinationFileName="native.zip"/>
-    <Unzip DestinationFolder="$(TempExtractPath)"
+    <!-- Nightly artifacts wrap the native archive in an outer platform zip. -->
+    <Unzip Condition="'$(DownloadNative)' == 'true' AND '$(InnerZipName)' != ''"
+           DestinationFolder="$(TempExtractPath)"
            SourceFiles="$(NativeZipPath)"/>
-    <Unzip DestinationFolder="$(MSBuildProjectDirectory)\obj\runtimes\$(Rid)\native"
+    <Unzip Condition="'$(DownloadNative)' == 'true' AND '$(InnerZipName)' != ''"
+           DestinationFolder="$(NativeDirectory)"
            SourceFiles="$(TempExtractPath)\$(InnerZipName)"/>
-    <RemoveDir Directories="$(TempExtractPath)" />
-    <Delete Files="$(NativeZipPath)"/>
+    <RemoveDir Directories="$(TempExtractPath)"
+               Condition="'$(DownloadNative)' == 'true' AND '$(InnerZipName)' != ''" />
+    <Delete Files="$(NativeZipPath)"
+            Condition="'$(DownloadNative)' == 'true'"/>
+    <WriteLinesToFile File="$(NativeSourceStampPath)"
+                      Lines="$(LibUrl)"
+                      Overwrite="true"
+                      Condition="'$(DownloadNative)' == 'true'"/>
   </Target>
 
 </Project>
diff --git a/DuckDB.NET.Bindings/DuckDBStatementType.cs b/DuckDB.NET.Bindings/DuckDBStatementType.cs
@@ -3,32 +3,36 @@
 public enum DuckDBStatementType
 {
     Invalid = 0,
-    Select,
-    Insert,
-    Update,
-    Explain,
-    Delete,
-    Prepare,
-    Create,
-    Execute,
-    Alter,
-    Transaction,
-    Copy,
-    Analyze,
-    VariableSet,
-    CreateFunc,
-    Drop,
-    Export,
-    Pragma,
-    Show,
-    Vacuum,
-    Call,
-    Set,
-    Load,
-    Relation,
-    Extension,
-    LogicalPlan,
-    Attach,
-    Detach,
-    Multi,
-}
+    Select = 1,
+    Insert = 2,
+    Update = 3,
+    Explain = 4,
+    Delete = 5,
+    Prepare = 6,
+    Create = 7,
+    Execute = 8,
+    Alter = 9,
+    Transaction = 10,
+    Copy = 11,
+    Analyze = 12,
+    VariableSet = 13,
+    CreateFunc = 14,
+    Drop = 15,
+    Export = 16,
+    Pragma = 17,
+    [Obsolete("DuckDB reports SHOW statements as Select.")]
+    Show = Select,
+    Vacuum = 18,
+    Call = 19,
+    Set = 20,
+    Load = 21,
+    Relation = 22,
+    Extension = 23,
+    LogicalPlan = 24,
+    Attach = 25,
+    Detach = 26,
+    Multi = 27,
+    CopyDatabase = 28,
+    UpdateExtensions = 29,
+    MergeInto = 30,
+}
diff --git a/DuckDB.NET.Data/Data.csproj b/DuckDB.NET.Data/Data.csproj
@@ -14,7 +14,7 @@ Fixes:
     <Description Condition="'$(ForkPreview)' == 'true'">Unofficial preview build of the DuckDB ADO.NET provider from the skuirrels DuckDB.NET fork.</Description>
     <PackageReleaseNotes Condition="'$(ForkPreview)' == 'true'">Unofficial preview of the consolidated DuckDB.NET performance work for DuckDB v1.5.4. Do not reference this package alongside the official DuckDB.NET packages.</PackageReleaseNotes>
     <Description Condition="'$(ForkRelease)' == 'true'">Unofficial stable build of the DuckDB ADO.NET provider from the skuirrels DuckDB.NET fork.</Description>
-    <PackageReleaseNotes Condition="'$(ForkRelease)' == 'true'">Stable fork release of the consolidated DuckDB.NET performance work for DuckDB v1.5.4. Do not reference this package alongside the official DuckDB.NET packages.</PackageReleaseNotes>
+    <PackageReleaseNotes Condition="'$(ForkRelease)' == 'true'">Stable fork release of the consolidated DuckDB.NET performance work for DuckDB v$(DuckDbNativeVersion). Do not reference this package alongside the official DuckDB.NET packages.</PackageReleaseNotes>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>..\keyPair.snk</AssemblyOriginatorKeyFile>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>

diff --git a/DuckDB.NET.Test/DuckDB155CompatibilityTests.cs b/DuckDB.NET.Test/DuckDB155CompatibilityTests.cs
@@ -0,0 +1,60 @@
+namespace DuckDB.NET.Test;
+
+public class DuckDB155CompatibilityTests(DuckDBDatabaseFixture db) : DuckDBTestBase(db)
+{
+    [Fact]
+    public void MergeIntoReturnsManagedStatementType()
+    {
+        Command.CommandText =
+            """
+            create table statement_type_target(id integer primary key, value varchar);
+            create table statement_type_source(id integer, value varchar);
+            insert into statement_type_target values (1, 'old');
+            insert into statement_type_source values (1, 'new'), (2, 'added');
+            """;
+        Command.ExecuteNonQuery();
+
+        var state = NativeMethods.Query.DuckDBQuery(
+            Connection.NativeConnection,
+            """
+            merge into statement_type_target
+            using statement_type_source
+            on statement_type_target.id = statement_type_source.id
+            when matched then update set value = statement_type_source.value
+            when not matched then
+                insert (id, value) values (statement_type_source.id, statement_type_source.value)
+            """,
+            out var result);
+
+        try
+        {
+            state.Should().Be(DuckDBState.Success);
+            NativeMethods.Query.DuckDBResultStatementType(result)
+                .Should().Be(DuckDBStatementType.MergeInto);
+        }
+        finally
+        {
+            NativeMethods.Query.DuckDBDestroyResult(ref result);
+        }
+    }
+
+    [Fact]
+    public void ShowIsReportedAsSelect()
+    {
+        var state = NativeMethods.Query.DuckDBQuery(
+            Connection.NativeConnection,
+            "show tables",
+            out var result);
+
+        try
+        {
+            state.Should().Be(DuckDBState.Success);
+            NativeMethods.Query.DuckDBResultStatementType(result)
+                .Should().Be(DuckDBStatementType.Select);
+        }
+        finally
+        {
+            NativeMethods.Query.DuckDBDestroyResult(ref result);
+        }
+    }
+}
diff --git a/README-FORK.md b/README-FORK.md
@@ -2,13 +2,13 @@
 
 This is an unofficial stable build from the
 [`skuirrels/DuckDB.NET`](https://github.com/skuirrels/DuckDB.NET) fork. It
-packages the consolidated performance work for DuckDB v1.5.4 under distinct
+packages the consolidated performance work for DuckDB v1.5.5 under distinct
 `Skuirrels.DuckDB.NET.*` package IDs.
 
 Install the bundled provider explicitly:
 
 ```shell
-dotnet add package Skuirrels.DuckDB.NET.Data.Full --version 1.5.5
+dotnet add package Skuirrels.DuckDB.NET.Data.Full --version 1.5.5.2
 ```
 
 NuGet packages:
@@ -21,7 +21,7 @@ so application source code does not need to change. Do not reference this fork
 package and the official `DuckDB.NET.Data.Full` package in the same dependency
 graph because they contain assemblies with the same identities.
 
-This release bundles DuckDB v1.5.4 and includes the consolidated appender,
+This release bundles DuckDB v1.5.5 and includes the consolidated appender,
 parameter binding, prepared-command, result materialisation, and scoped-writer
 optimisations from the fork. When equivalent upstream changes are released,
 move back to the official `DuckDB.NET.Data.Full` package.

diff --git a/README.md b/README.md
@@ -13,7 +13,7 @@ the corresponding upstream pull requests are reviewed and released.
 ## Usage
 
 ```sh
-dotnet add package Skuirrels.DuckDB.NET.Data.Full --version 1.5.5
+dotnet add package Skuirrels.DuckDB.NET.Data.Full --version 1.5.5.2
 ```
 
 The fork packages retain the official `DuckDB.NET.Data` namespaces and assembly

diff --git a/scripts/validate-fork-packages.sh b/scripts/validate-fork-packages.sh
@@ -109,7 +109,7 @@ using (var appender = connection.CreateAppender("fork_package_smoke"))
 using var verification = connection.CreateCommand();
 verification.CommandText = "SELECT version(), sum(value) FROM fork_package_smoke";
 using var reader = verification.ExecuteReader();
-if (!reader.Read() || !reader.GetString(0).Contains("v1.5.4", StringComparison.Ordinal) || reader.GetInt64(1) != 42)
+if (!reader.Read() || !reader.GetString(0).Contains("v1.5.5", StringComparison.Ordinal) || reader.GetInt64(1) != 42)
 {
     throw new InvalidOperationException("Fork package smoke test failed.");
 }