Consider the settings files location in project configuration

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/embedder/MavenProperties.java

@@ -237,6 +237,20 @@ public static void getCliProperties(CommandLine commandLine, BiConsumer<String,
     }
   }
 
+  public static String getAlternateGlobalToolchainsFile(CommandLine commandline) {
+    if(commandline != null && commandline.hasOption(CLIManager.ALTERNATE_GLOBAL_TOOLCHAINS)) {
+      return commandline.getOptionValue(CLIManager.ALTERNATE_USER_SETTINGS);
+    }
+    return null;
+  }
+
+  public static String getAlternateUserToolchainsFile(CommandLine commandline) {
+    if(commandline != null && commandline.hasOption(CLIManager.ALTERNATE_USER_TOOLCHAINS)) {
+      return commandline.getOptionValue(CLIManager.ALTERNATE_USER_TOOLCHAINS);
+    }
+    return null;
+  }
+
   public static void getCliProperty(String property, BiConsumer<String, String> consumer) {
     int index = property.indexOf('=');
     if(index <= 0) {

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/project/registry/MavenProjectFacade.java

@@ -664,6 +664,10 @@ private static final class MavenProjectConfiguration implements IProjectConfigur
 
     private List<String> inactiveProfiles;
 
+    private String globalSettingsFile;
+
+    private String userSettingsFile;
+
     private MavenProjectConfiguration(IProjectConfiguration baseConfiguration) {
       if(baseConfiguration == null) {
         //we should really forbid this but some test seem to pass null!
@@ -677,6 +681,8 @@ private MavenProjectConfiguration(IProjectConfiguration baseConfiguration) {
       this.profiles = baseConfiguration.getSelectedProfiles();
       this.activeProfiles = List.copyOf(baseConfiguration.getActiveProfileList());
       this.inactiveProfiles = List.copyOf(baseConfiguration.getInactiveProfileList());
+      this.globalSettingsFile = baseConfiguration.getGlobalSettingsFile();
+      this.userSettingsFile = baseConfiguration.getUserSettingsFile();
     }
 
     @Override
@@ -735,6 +741,16 @@ public List<String> getInactiveProfileList() {
       return inactiveProfiles;
     }
 
+    @Override
+    public String getGlobalSettingsFile() {
+      return globalSettingsFile;
+    }
+
+    @Override
+    public String getUserSettingsFile() {
+      return userSettingsFile;
+    }
+
   }
 
 

org.eclipse.m2e.core/src/org/eclipse/m2e/core/project/IProjectConfiguration.java

@@ -54,6 +54,10 @@ public interface IProjectConfiguration {
 
   File getMultiModuleProjectDirectory();
 
+  String getGlobalSettingsFile();
+
+  String getUserSettingsFile();
+
   /**
    * Computes a hashcode over the contents of the given configuration, that is a semantic hash-code that can be used in
    * combination of {@link #contentsEquals(IProjectConfiguration, IProjectConfiguration)}
@@ -65,7 +69,8 @@ public static int contentsHashCode(IProjectConfiguration configuration) {
     return Objects.hash(configuration.isResolveWorkspaceProjects(), configuration.getActiveProfileList(),
         configuration.getInactiveProfileList(), configuration.getLifecycleMappingId(),
         configuration.getConfigurationProperties(), configuration.getUserProperties(),
-        configuration.getMultiModuleProjectDirectory());
+        configuration.getMultiModuleProjectDirectory(), configuration.getGlobalSettingsFile(),
+        configuration.getUserSettingsFile());
   }
 
   public static boolean contentsEquals(IProjectConfiguration configuration, IProjectConfiguration other) {
@@ -81,7 +86,9 @@ public static boolean contentsEquals(IProjectConfiguration configuration, IProje
         && Objects.equals(configuration.getInactiveProfileList(), other.getInactiveProfileList())
         && Objects.equals(configuration.getConfigurationProperties(), other.getConfigurationProperties())
         && Objects.equals(configuration.getUserProperties(), other.getUserProperties())
-        && Objects.equals(configuration.getMultiModuleProjectDirectory(), other.getMultiModuleProjectDirectory());
+        && Objects.equals(configuration.getMultiModuleProjectDirectory(), other.getMultiModuleProjectDirectory())
+        && Objects.equals(configuration.getGlobalSettingsFile(), other.getGlobalSettingsFile())
+        && Objects.equals(configuration.getUserSettingsFile(), other.getUserSettingsFile());
   }
 
 }

org.eclipse.m2e.core/src/org/eclipse/m2e/core/project/ResolverConfiguration.java

@@ -66,6 +66,10 @@ public class ResolverConfiguration implements Serializable, IProjectConfiguratio
 
   private List<String> userInactiveProfiles;
 
+  private String globalSettingsFile;
+
+  private String userSettingsFile;
+
   public ResolverConfiguration() {
   }
 
@@ -79,9 +83,9 @@ public ResolverConfiguration(IProject project) {
   public ResolverConfiguration(IProjectConfiguration resolverConfiguration) {
     setLifecycleMappingId(resolverConfiguration.getLifecycleMappingId());
     setMultiModuleProjectDirectory(resolverConfiguration.getMultiModuleProjectDirectory());
-    Properties properties2 = new Properties();
-    properties2.putAll(resolverConfiguration.getConfigurationProperties());
-    setProperties(properties2);
+    Properties properties = new Properties();
+    properties.putAll(resolverConfiguration.getConfigurationProperties());
+    setProperties(properties);
     setResolveWorkspaceProjects(resolverConfiguration.isResolveWorkspaceProjects());
     setSelectedProfiles(resolverConfiguration.getSelectedProfiles());
   }
@@ -195,6 +199,16 @@ public File getMultiModuleProjectDirectory() {
     return multiModuleProjectDirectory;
   }
 
+  @Override
+  public String getGlobalSettingsFile() {
+    return globalSettingsFile;
+  }
+
+  @Override
+  public String getUserSettingsFile() {
+    return userSettingsFile;
+  }
+
   /**
    * @param multiModuleProjectDirectory The multiModuleProjectDirectory to set.
    */
@@ -209,6 +223,8 @@ public void setMultiModuleProjectDirectory(File multiModuleProjectDirectory) {
         userActiveProfiles = new ArrayList<>();
         userInactiveProfiles = new ArrayList<>();
         MavenProperties.getProfiles(commandLine, userActiveProfiles::add, userInactiveProfiles::add);
+        globalSettingsFile = MavenProperties.getAlternateGlobalToolchainsFile(commandLine);
+        userSettingsFile = MavenProperties.getAlternateUserToolchainsFile(commandLine);
       } catch(IOException | ParseException ex) {
         //can't use it then... :-(
         MavenPluginActivator.getDefault().getLog().error("can't read maven args from " + multiModuleProjectDirectory,