diff --git a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/DefaultHookHandler.java b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/DefaultHookHandler.java
index f4d8ba2a08..b7ebefca3b 100644
--- a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/DefaultHookHandler.java
+++ b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/DefaultHookHandler.java
@@ -68,11 +68,13 @@ class DefaultHookHandler implements HookHandler {
 
   @Override
   public void run() {
+    LOG.trace("start handling hook protocol");
     try (InputStream input = socket.getInputStream(); OutputStream output = socket.getOutputStream()) {
       handleHookRequest(input, output);
     } catch (IOException e) {
       LOG.warn("failed to read hook request", e);
     } finally {
+      LOG.trace("close client socket");
       close();
     }
   }
@@ -84,8 +86,10 @@ class DefaultHookHandler implements HookHandler {
   }
 
   private Response handleHookRequest(Request request) {
+    LOG.trace("process {} hook for node {}", request.getType(), request.getNode());
     try {
       if (!environment.isAcceptAble(request.getChallenge())) {
+        LOG.warn("received hook with invalid challenge: {}", request.getChallenge());
         return error("invalid hook challenge");
       }
 
@@ -111,6 +115,7 @@ class DefaultHookHandler implements HookHandler {
   }
 
   private void authenticate(Request request) {
+    LOG.trace("authenticate hook request");
     String token = CipherUtil.getInstance().decode(request.getToken());
     BearerToken bearer = BearerToken.valueOf(token);
     Subject subject = SecurityUtils.getSubject();
diff --git a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/HookServer.java b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/HookServer.java
index 40fb4a68e3..ac27323018 100644
--- a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/HookServer.java
+++ b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/HookServer.java
@@ -96,6 +96,7 @@ public class HookServer implements AutoCloseable {
     acceptor.submit(() -> {
       while (!serverSocket.isClosed()) {
         try {
+          LOG.trace("wait for next hook connection");
           Socket clientSocket = serverSocket.accept();
           LOG.trace("accept incoming hook client from {}", clientSocket.getInetAddress());
           HookHandler hookHandler = handlerFactory.create(clientSocket);
@@ -104,6 +105,7 @@ public class HookServer implements AutoCloseable {
           LOG.debug("failed to accept socket, possible closed", ex);
         }
       }
+      LOG.warn("ServerSocket is closed");
     });
   }
 
diff --git a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/Sockets.java b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/Sockets.java
index e6b748643b..9791e99c31 100644
--- a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/Sockets.java
+++ b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/Sockets.java
@@ -42,6 +42,7 @@ class Sockets {
     byte[] bytes = objectMapper.writeValueAsBytes(object);
     out.write(bytes);
     out.write('\0');
+    out.flush();
   }
 
   static <T> T read(InputStream in, Class<T> type) throws IOException {
diff --git a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgModifyCommand.java b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgModifyCommand.java
index 012592c7a4..10e444b03a 100644
--- a/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgModifyCommand.java
+++ b/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgModifyCommand.java
@@ -31,6 +31,8 @@ import com.aragost.javahg.commands.ExecutionException;
 import com.aragost.javahg.commands.PullCommand;
 import com.aragost.javahg.commands.RemoveCommand;
 import com.aragost.javahg.commands.StatusCommand;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import sonia.scm.NoChangesMadeException;
 import sonia.scm.repository.InternalRepositoryException;
 import sonia.scm.repository.work.WorkingCopy;
@@ -40,9 +42,12 @@ import java.io.IOException;
 import java.nio.file.Path;
 import java.util.List;
 
+@SuppressWarnings("java:S3252") // it is ok for javahg classes to access static method of subtype
 public class HgModifyCommand implements ModifyCommand {
 
-  private HgCommandContext context;
+  private static final Logger LOG = LoggerFactory.getLogger(HgModifyCommand.class);
+
+  private final HgCommandContext context;
   private final HgWorkingCopyFactory workingCopyFactory;
 
   public HgModifyCommand(HgCommandContext context, HgWorkingCopyFactory workingCopyFactory) {
@@ -52,7 +57,6 @@ public class HgModifyCommand implements ModifyCommand {
 
   @Override
   public String execute(ModifyCommandRequest request) {
-
     try (WorkingCopy<com.aragost.javahg.Repository, com.aragost.javahg.Repository> workingCopy = workingCopyFactory.createWorkingCopy(context, request.getBranch())) {
       Repository workingRepository = workingCopy.getWorkingRepository();
       request.getRequests().forEach(
@@ -97,12 +101,21 @@ public class HgModifyCommand implements ModifyCommand {
           }
         }
       );
+
       if (StatusCommand.on(workingRepository).lines().isEmpty()) {
         throw new NoChangesMadeException(context.getScmRepository());
       }
-      CommitCommand.on(workingRepository).user(String.format("%s <%s>", request.getAuthor().getName(), request.getAuthor().getMail())).message(request.getCommitMessage()).execute();
+
+      LOG.trace("commit changes in working copy");
+      CommitCommand.on(workingRepository)
+        .user(String.format("%s <%s>", request.getAuthor().getName(), request.getAuthor().getMail()))
+        .message(request.getCommitMessage()).execute();
+
       List<Changeset> execute = pullModifyChangesToCentralRepository(request, workingCopy);
-      return execute.get(0).getNode();
+
+      String node = execute.get(0).getNode();
+      LOG.debug("successfully pulled changes from working copy, new node {}", node);
+      return node;
     } catch (ExecutionException e) {
       throwInternalRepositoryException("could not execute command on repository", e);
       return null;
@@ -110,6 +123,7 @@ public class HgModifyCommand implements ModifyCommand {
   }
 
   private List<Changeset> pullModifyChangesToCentralRepository(ModifyCommandRequest request, WorkingCopy<com.aragost.javahg.Repository, com.aragost.javahg.Repository> workingCopy) {
+    LOG.trace("pull changes from working copy");
     try {
       com.aragost.javahg.commands.PullCommand pullCommand = PullCommand.on(workingCopy.getCentralRepository());
       workingCopyFactory.configure(pullCommand);