Ignore missing AWT library if missing

- This is a workaround until oracle/graal#4124 is fixed

deployment/src/main/java/io/quarkiverse/poi/deployment/POIProcessor.java

@@ -12,6 +12,7 @@
 import io.quarkus.deployment.builditem.FeatureBuildItem;
 import io.quarkus.deployment.builditem.IndexDependencyBuildItem;
 import io.quarkus.deployment.builditem.NativeImageFeatureBuildItem;
+import io.quarkus.deployment.builditem.SystemPropertyBuildItem;
 import io.quarkus.deployment.builditem.nativeimage.ReflectiveClassBuildItem;
 
 class POIProcessor {
@@ -34,6 +35,11 @@ void indexTransitiveDependencies(BuildProducer<IndexDependencyBuildItem> index)
         index.produce(new IndexDependencyBuildItem("org.apache.poi", "poi-ooxml-full"));
     }
 
+    @BuildStep
+    SystemPropertyBuildItem ignoreMissingFontSystem() {
+        return new SystemPropertyBuildItem("org.apache.poi.ss.ignoreMissingFontSystem", "true");
+    }
+
     @BuildStep
     void registerXMLBeansClassesForReflection(CombinedIndexBuildItem combinedIndexBuildItem,
             BuildProducer<ReflectiveClassBuildItem> reflectiveClass) {

runtime/src/main/java/io/quarkiverse/poi/runtime/graal/SheetUtilSubstitution.java

@@ -0,0 +1,34 @@
+package io.quarkiverse.poi.runtime.graal;
+
+import java.text.AttributedString;
+
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.util.SheetUtil;
+import org.graalvm.nativeimage.Platform;
+import org.graalvm.nativeimage.Platforms;
+
+import com.oracle.svm.core.annotate.Alias;
+import com.oracle.svm.core.annotate.RecomputeFieldValue;
+import com.oracle.svm.core.annotate.Substitute;
+import com.oracle.svm.core.annotate.TargetClass;
+
+@TargetClass(SheetUtil.class)
+@Platforms(Platform.MACOS.class)
+public final class SheetUtilSubstitution {
+
+    @Alias
+    @RecomputeFieldValue(kind = RecomputeFieldValue.Kind.FromAlias)
+    public static int DEFAULT_CHAR_WIDTH = 5;
+
+    @Substitute
+    public static int getDefaultCharWidth(final Workbook wb) {
+        return DEFAULT_CHAR_WIDTH;
+    }
+
+    @Substitute
+    private static double getCellWidth(int defaultCharWidth, int colspan,
+            CellStyle style, double minWidth, AttributedString str) {
+        return defaultCharWidth;
+    }
+}