Tweak changelog gen logic

build.gradle

@@ -200,17 +200,24 @@ modrinth {
     uploadFile = remapJar
     gameVersions = [minecraft_version]
     loaders = ["forge"]
-    File changelogFile = new File("./CHANGELOG.md")
-    if (changelogFile.exists())
-        changelog = changelogFile.getText('UTF-8')
-    else
-        changelog = "No changelog was provided."
+    changelog.set(provider { file("./CHANGELOG.md").getText('UTF-8') })
 }
 
+tasks.register('checkCleanTag') {
+    doLast {
+        def details = versionDetails()
+        if (!details.isCleanTag || versionDetails().commitDistance != 0) {
+            throw new GradleException('Not a clean tree.')
+        }
+    }
+}
+
+tasks.curseforge.dependsOn(":checkCleanTag")
 tasks.curseforge.dependsOn(":generateChangelog")
+tasks.modrinth.dependsOn(":checkCleanTag")
 tasks.modrinth.dependsOn(":generateChangelog")
 
-task publishToModSites {
-    publishToModSites.dependsOn modrinth
-    publishToModSites.dependsOn curseforge
+tasks.register('publishToModSites') {
+    publishToModSites.dependsOn(tasks.modrinth)
+    publishToModSites.dependsOn(tasks.curseforge)
 }