diff --git a/.github/workflows/dart.yml b/.github/workflows/dart.yml
index a2611bf37..599854a92 100644
--- a/.github/workflows/dart.yml
+++ b/.github/workflows/dart.yml
@@ -19,18 +19,36 @@ jobs:
         run: ./generator/test.sh
 
   lib:
-    runs-on: ubuntu-20.04
-    container:
-      image: google/dart:latest
+    strategy:
+      matrix:
+        os:
+          - windows-2019
+          - macos-10.15
+          - ubuntu-20.04
+        dart:
+          - 2.10.5
+          # - 2.9.3 - generator stuck. I remember there was an issue in some dependency but don't remember which one.
+          - 2.8.4
+          - 2.7.2
+    runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v1
+      # Note: dart-sdk from flutter doesn't work on linux, see https://github.com/flutter/flutter/issues/74599
+      #      - uses: subosito/flutter-action@v1
+      #        with:
+      #          flutter-version: 1.22.x
+      #      - run: flutter --version
+      - uses: cedx/setup-dart@v2
+        with:
+          version: ${{ matrix.dart }}
+      - run: dart --version
+      - uses: actions/checkout@v2
       - name: Install ObjectBox C-API
         run: ./install.sh
-      - run: pub get
+      - run: ./tool/pub.sh get
       - name: Generate ObjectBox models
-        run: pub run build_runner build
+        run: ./tool/pub.sh run build_runner build
       - name: Run tests
-        run: pub run test
+        run: ./tool/pub.sh run test
 
   valgrind:
     runs-on: ubuntu-20.04
@@ -47,4 +65,4 @@ jobs:
         run: |
           apt update
           apt install -y valgrind
-      - run: ./tool/valgrind.sh
\ No newline at end of file
+      - run: ./tool/valgrind.sh
diff --git a/lib/src/bindings/bindings.dart b/lib/src/bindings/bindings.dart
index e75223fa0..e0e965a3f 100644
--- a/lib/src/bindings/bindings.dart
+++ b/lib/src/bindings/bindings.dart
@@ -11,8 +11,18 @@ ObjectBoxC loadObjectBoxLib() {
   var libName = 'objectbox';
   if (Platform.isWindows) {
     libName += '.dll';
+    try {
+      lib = DynamicLibrary.open(libName);
+    } on ArgumentError {
+      lib = DynamicLibrary.open('lib/' + libName);
+    }
   } else if (Platform.isMacOS) {
     libName = 'lib' + libName + '.dylib';
+    try {
+      lib = DynamicLibrary.open(libName);
+    } on ArgumentError {
+      lib = DynamicLibrary.open('/usr/local/lib/' + libName);
+    }
   } else if (Platform.isIOS) {
     // this works in combination with `'OTHER_LDFLAGS' => '-framework ObjectBox'` in objectbox_flutter_libs.podspec
     lib = DynamicLibrary.process();
diff --git a/lib/src/bindings/flatbuffers.dart b/lib/src/bindings/flatbuffers.dart
index 0fb0cded2..bc61549d3 100644
--- a/lib/src/bindings/flatbuffers.dart
+++ b/lib/src/bindings/flatbuffers.dart
@@ -2,6 +2,7 @@ import 'dart:typed_data';
 
 import 'package:ffi/ffi.dart' as f;
 import 'dart:ffi';
+import 'dart:io' show Platform;
 
 import '../../flatbuffers/flat_buffers.dart' as fb;
 
@@ -80,8 +81,30 @@ class _Allocator extends fb.Allocator {
 
   @override
   void clear(ByteData data, bool _) {
-    _memset ??= DynamicLibrary.process().lookupFunction<
-        Void Function(Pointer<Void>, Int32, IntPtr), _dart_memset>('memset');
+    if (_memset == null) {
+      try {
+        DynamicLibrary lib;
+        if (Platform.isWindows) {
+          // DynamicLibrary.process() is not available on Windows, let's load a
+          // lib that defines 'memset()' it - should be mscvr100 or mscvrt DLL.
+          // mscvr100.dll is in the frequently installed MSVC Redistributable.
+          lib = DynamicLibrary.open('msvcr100.dll');
+        } else {
+          lib = DynamicLibrary.process();
+        }
+        _memset = lib.lookupFunction<
+            Void Function(Pointer<Void>, Int32, IntPtr),
+            _dart_memset>('memset');
+      } catch (_) {
+        // fall back if we can't load a native memset()
+        _memset = (Pointer<Void> ptr, int byte, int size) {
+          final bytes = ptr.cast<Uint8>();
+          for (var i = 0; i < size; i++) {
+            bytes[i] = byte;
+          }
+        };
+      }
+    }
     _memset(_allocs[data].cast<Void>(), 0, data.lengthInBytes);
   }
 }
diff --git a/lib/src/query/query.dart b/lib/src/query/query.dart
index ad0fc906e..ec234d7c6 100644
--- a/lib/src/query/query.dart
+++ b/lib/src/query/query.dart
@@ -754,7 +754,7 @@ class Query<T> {
     try {
       final idArray = idArrayPtr.ref;
       return idArray.count == 0
-          ? List<int>.empty()
+          ? List<int>.filled(0, 0)
           : idArray.ids.asTypedList(idArray.count).toList(growable: false);
     } finally {
       C.id_array_free(idArrayPtr);
diff --git a/pubspec.yaml b/pubspec.yaml
index 4507d2341..1856ea771 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -6,7 +6,8 @@ description: ObjectBox is a super-fast NoSQL ACID compliant object database.
 
 environment:
   #  sdk: '>=2.12.0-0 <3.0.0'
-  sdk: '>=2.6.0 <3.0.0'
+  # min 2.7.0 because of ffigen
+  sdk: '>=2.7.0 <3.0.0'
 
 dependencies:
   collection: ^1.14.11
@@ -20,8 +21,8 @@ dev_dependencies:
   build_runner: ^1.0.0
   objectbox_generator:
     path: generator
-  pedantic: ^1.10.0-nullsafety.0
-  test: ^1.16.0-nullsafety.0
+  pedantic: ^1.9.0
+  test: ^1.0.0
   ffigen: ^1.1.0
   flat_buffers: 1.12.0
 
diff --git a/tool/pub.sh b/tool/pub.sh
new file mode 100755
index 000000000..b9ed4b573
--- /dev/null
+++ b/tool/pub.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# forward all arguments to an available version of `pub`
+
+if [[ `command -v pub` ]]; then
+  pub "$@"
+elif [[ `command -v pub.bat` ]]; then
+  pub.bat "$@"
+else
+  dart pub "$@"
+fi