Resolve and apply settings buildscript dependencies

app/src/dist/share/gradle-env.nix

@@ -32,12 +32,12 @@
 
 let
   inherit (builtins)
-    filter sort replaceStrings attrValues match fromJSON
-    concatStringsSep;
+    attrValues concatStringsSep filter fromJSON match replaceStrings sort;
 
   inherit (stdenv.lib)
-    versionOlder unique mapAttrs mapAttrsToList last concatMapStringsSep
-    removeSuffix optionalString groupBy' readFile hasSuffix;
+    assertMsg concatMapStringsSep groupBy' hasSuffix last mapAttrs
+    mapAttrsToList optionalString readFile removeSuffix unique versionAtLeast
+    versionOlder;
 
   mkDep = depSpec: stdenv.mkDerivation {
     inherit (depSpec) name;
@@ -176,10 +176,20 @@ let
     paths = map mkDep deps ++ mkModuleMetadata deps ++ mkSnapshotMetadata deps;
   };
 
-  mkInitScript = projectSpec:
+  mkInitScript = projectSpec: gradle:
     let
       repos = mapAttrs (mkRepo projectSpec.name) projectSpec.dependencies;
+      hasDependencies = mapAttrs (type: deps: deps != []) projectSpec.dependencies;
     in
+      assert (assertMsg (hasDependencies.settings -> versionAtLeast gradle.version "6.0") ''
+        Project `${projectSpec.name}' has settings script dependencies, such as settings
+        plugins, which are not supported by gradle2nix for Gradle versions prior to 6.0.
+
+        Potential remedies:
+        - Pass `--gradle-version=<version>' to the gradle2nix command.
+        - Patch the `settings.gradle[.kts]' file to remove script dependencies.
+      '');
+
       writeText "init.gradle" ''
         static def offlineRepo(RepositoryHandler repositories, String env, String path) {
             repositories.clear()
@@ -204,18 +214,35 @@ let
             }
         }
 
-        gradle.settingsEvaluated {
-            offlineRepo(it.pluginManagement.repositories, "plugin", "${repos.plugin}")
-        }
+        ${optionalString (hasDependencies.settings && (versionAtLeast gradle.version "6.0")) ''
+          gradle.beforeSettings {
+              offlineRepo(it.buildscript.repositories, "settings", "${repos.settings}")
+          }
+        ''}
 
-        gradle.projectsLoaded {
-            allprojects {
-                buildscript {
-                    offlineRepo(repositories, "buildscript", "${repos.buildscript}")
-                }
-                offlineRepo(repositories, "project", "${repos.project}")
-            }
-        }
+        ${optionalString (hasDependencies.plugin) ''
+          gradle.settingsEvaluated {
+              offlineRepo(it.pluginManagement.repositories, "plugin", "${repos.plugin}")
+          }
+        ''}
+
+        ${optionalString (hasDependencies.buildscript) ''
+          gradle.projectsLoaded {
+              allprojects {
+                  buildscript {
+                      offlineRepo(repositories, "buildscript", "${repos.buildscript}")
+                  }
+              }
+          }
+        ''}
+
+        ${optionalString (hasDependencies.project) ''
+          gradle.projectsLoaded {
+              allprojects {
+                  offlineRepo(repositories, "project", "${repos.project}")
+              }
+          }
+        ''}
       '';
 
   mkGradle = gradleSpec:
@@ -227,12 +254,14 @@ let
       src = fetchurl {
         inherit (gradleSpec) url sha256;
       };
+    } // {
+      inherit (gradleSpec) version;
     };
 
-  mkProjectEnv = projectSpec: {
+  mkProjectEnv = projectSpec: rec {
     inherit (projectSpec) name path version;
-    initScript = mkInitScript projectSpec;
     gradle = args.gradlePackage or mkGradle projectSpec.gradle;
+    initScript = mkInitScript projectSpec gradle;
   };
 
   gradleEnv = mapAttrs

app/src/main/kotlin/org/nixos/gradle2nix/Env.kt

@@ -19,6 +19,7 @@ fun buildEnv(builds: Map<String, DefaultBuild>): Map<String, NixGradleEnv> =
             path = path,
             gradle = build.gradle,
             dependencies = mapOf(
+                "settings" to build.settingsDependencies,
                 "plugin" to build.pluginDependencies,
                 "buildscript" to build.rootProject.collectDependencies(DefaultProject::buildscriptDependencies),
                 "project" to build.rootProject.collectDependencies(DefaultProject::projectDependencies)