build with gradle 7, since we're all forced into J16 workspaces now...

build.gradle.kts

@@ -29,7 +29,7 @@ subprojects {
     }
 
     dependencies {
-        "compileOnlyApi"("org.checkerframework:checker-qual:3.12.0")
+        "compileOnlyApi"("org.checkerframework:checker-qual:3.13.0")
     }
 
     val indraGit = extensions.getByType(net.kyori.indra.git.IndraGitExtension::class)

convention/build.gradle.kts

@@ -11,7 +11,7 @@ tasks.withType(GroovyCompile::class).configureEach {
 dependencies {
     api(project(":spongegradle-plugin-development"))
     implementation(localGroovy())
-    api("net.kyori:indra-common:2.0.2")
+    api("net.kyori:indra-common:2.0.4")
     api("gradle.plugin.org.cadixdev.gradle:licenser:0.6.0")
     api("com.google.code.gson:gson:2.8.6")
 }

convention/src/main/groovy/org/spongepowered/gradle/convention/SpongeConventionPlugin.java

@@ -36,6 +36,7 @@
 import org.gradle.api.GradleException;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
+import org.gradle.api.java.archives.Attributes;
 import org.gradle.api.java.archives.Manifest;
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginConvention;
@@ -105,14 +106,13 @@ public void apply(final Project target) {
 
     private void configureJarTasks(final Manifest manifest, final IndraGitExtension git) {
         // Add some standard attributes
-        final Map<String, Object> attributes = new HashMap<>();
-        attributes.put("Specification-Title", this.project.getName());
-        attributes.put("Specification-Vendor", "SpongePowered");
-        attributes.put("Specification-Version", this.project.getVersion());
-        attributes.put("Implementation-Title", this.project.getName());
-        attributes.put("Implementation-Vendor", "SpongePowered");
-        attributes.put("Implementation-Version", this.project.getVersion());
-        manifest.attributes(attributes);
+        final Attributes attributes = manifest.getAttributes();
+        attributes.putIfAbsent("Specification-Title", this.project.getName());
+        attributes.putIfAbsent("Specification-Vendor", "SpongePowered");
+        attributes.putIfAbsent("Specification-Version", this.project.getVersion());
+        attributes.putIfAbsent("Implementation-Title", this.project.getName());
+        attributes.putIfAbsent("Implementation-Vendor", "SpongePowered");
+        attributes.putIfAbsent("Implementation-Version", this.project.getVersion());
         git.applyVcsInformationToManifest(manifest);
     }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

plugin-development/src/functionalTest/java/org/spongepowered/gradle/plugin/SpongePluginPluginFunctionalTest.java

@@ -139,9 +139,9 @@ Stream<DynamicTest> functionalTests(@TempDir final Path runDirectory) {
         // Test variants
         final String[][] variants = {
             {"6.8.3", ""},
-            {"7.0", ""},
+            {"7.0.2", ""},
             {"6.8.3", "--configuration-cache"},
-            {"7.0", "--configuration-cache"},
+            {"7.0.2", "--configuration-cache"},
         };
 
         // The actual tests to execute

settings.gradle.kts

@@ -6,7 +6,7 @@ pluginManagement {
     }
 
     plugins {
-        val indraVersion = "2.0.2"
+        val indraVersion = "2.0.4"
         id("com.gradle.plugin-publish") version "0.14.0"
         id("net.kyori.indra") version indraVersion
         id("net.kyori.indra.license-header") version indraVersion