diff --git a/.gitignore b/.gitignore
index 3a4e9284..2b51df24 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,5 @@ __pycache__
 venv
 venv2
 build
+docker-compose.override.yml
+/workspace
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 41e8453c..893f2a57 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
-  - repo: https://github.com/psf/black
-    rev: 25.1.0
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 25.11.0
     hooks:
     - id: black
   - repo: https://github.com/pycqa/flake8
diff --git a/Changelog.md b/Changelog.md
index 44a0011f..fc46e74f 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,6 +1,14 @@
 # CHANGELOG
 All notable changes to this project will be documented here.
 
+## [v2.9.0]
+- Install stack with GHCup (#626)
+- Fixed AI tester to report error when the specified `submission` file is not found (#663)
+- Updated docker image to use Ubuntu 24.04 (#668)
+- Fixed stack installation in Docker environment (#668)
+- Removed `click` from server requirements.txt file (#679)
+- Fixed bug in R tester setup that always triggered reinstallation of R dependencies (#680)
+
 ## [v2.8.3]
 - Add troubleshooting section talking about Docker Content Trust (DCT) (#653)
 - Fixed Python tester to display fully qualified name when running pytest (#656)
@@ -22,6 +30,7 @@ All notable changes to this project will be documented here.
 - Add `ai_tester` module to support AI-based autograding via `ai-autograding-feedback` (#625)
 - Add `ai` to list of testers (#628)
 - Fixed an `AttributeError` when handling exceptions in server `update_test_settings` (#629)
+- Add tag functionalty to `ai_tester` (#631)
 - Added opt out feature to the `ai_tester` by searching for `NO_EXTERNAL_AI_FEEDBACK` (#632)
 - Modified R tester to always display test result messages, even when tests pass (#633)
 
diff --git a/client/.dockerfiles/Dockerfile b/client/.dockerfiles/Dockerfile
index 2a8ca916..ebc4f1ca 100644
--- a/client/.dockerfiles/Dockerfile
+++ b/client/.dockerfiles/Dockerfile
@@ -1,7 +1,10 @@
-ARG UBUNTU_VERSION=22.04
+ARG UBUNTU_VERSION=24.04
 
 FROM ubuntu:$UBUNTU_VERSION
 
+# Remove ubuntu user, added in the 23.04 image
+RUN userdel -r ubuntu
+
 RUN apt-get update -y && \
     DEBIAN_FRONTEND=noninteractive apt-get -y install software-properties-common && \
     DEBIAN_FRONTEND=noninteractive add-apt-repository -y ppa:deadsnakes/ppa && \
diff --git a/client/requirements.txt b/client/requirements.txt
index 491f64bc..a9bf1f4c 100644
--- a/client/requirements.txt
+++ b/client/requirements.txt
@@ -1,6 +1,6 @@
-flask==3.1.1
-python-dotenv==1.1.1
-rq==2.4.1
-redis==6.2.0
-jsonschema==4.25.0
+flask==3.1.2
+python-dotenv==1.2.1
+rq==2.6.0
+redis==7.1.0
+jsonschema==4.25.1
 Werkzeug==3.1.3
diff --git a/compose.yaml b/compose.yaml
index 7239c6ec..39e38ec8 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -4,10 +4,10 @@ services:
       context: ./server
       dockerfile: ./.dockerfiles/Dockerfile
       args:
-        UBUNTU_VERSION: '22.04'
+        UBUNTU_VERSION: '24.04'
         LOGIN_USER: 'docker'
         WORKSPACE: '/home/docker/.autotesting'
-    image: markus-autotest-server-dev:1.3.0
+    image: markus-autotest-server-dev:1.4.0
     volumes:
       - ./server:/app:cached
       - venv_server:/home/docker/markus_venv
@@ -28,8 +28,8 @@ services:
       context: ./client
       dockerfile: ./.dockerfiles/Dockerfile
       args:
-        UBUNTU_VERSION: '22.04'
-    image: markus-autotest-client-dev:1.3.0
+        UBUNTU_VERSION: '24.04'
+    image: markus-autotest-client-dev:1.4.0
     container_name: 'autotest-client'
     volumes:
       - ./client:/app:cached
diff --git a/server/.dockerfiles/Dockerfile b/server/.dockerfiles/Dockerfile
index f587b85d..60ca5a48 100644
--- a/server/.dockerfiles/Dockerfile
+++ b/server/.dockerfiles/Dockerfile
@@ -1,7 +1,9 @@
-ARG UBUNTU_VERSION=22.04
+ARG UBUNTU_VERSION=24.04
 
 FROM ubuntu:$UBUNTU_VERSION AS base
 
+# Remove ubuntu user, added in the 23.04 image
+RUN userdel -r ubuntu
 
 ARG LOGIN_USER
 ARG WORKSPACE
@@ -29,6 +31,7 @@ RUN apt-get update -y && \
                        libharfbuzz-dev \
                        libfribidi-dev \
                        libxml2-dev \
+                       libnuma-dev \
                        r-base
 
 RUN useradd -ms /bin/bash $LOGIN_USER && \
@@ -37,9 +40,8 @@ RUN useradd -ms /bin/bash $LOGIN_USER && \
         adduser --disabled-login --no-create-home $worker && \
         echo "$LOGIN_USER ALL=($worker) NOPASSWD:ALL" | EDITOR="tee -a" visudo && \
         usermod -aG $worker $LOGIN_USER; \
-    done
-
-RUN chmod a+x /home/${LOGIN_USER}
+    done && \
+    chmod a+x /home/${LOGIN_USER}
 
 COPY . /app
 
@@ -47,8 +49,8 @@ RUN find /app/autotest_server/testers -name requirements.system -exec {} \;
 
 RUN echo "TZ=$( cat /etc/timezone )" >> /etc/R/Renviron.site
 
-RUN mkdir -p ${WORKSPACE} && chown ${LOGIN_USER} ${WORKSPACE}
-RUN mkdir -p /home/${LOGIN_USER}/markus_venv && chown ${LOGIN_USER} /home/${LOGIN_USER}/markus_venv
+RUN mkdir -p ${WORKSPACE} && chown ${LOGIN_USER} ${WORKSPACE} && \
+    mkdir -p /home/${LOGIN_USER}/markus_venv && chown ${LOGIN_USER} /home/${LOGIN_USER}/markus_venv
 
 WORKDIR /home/${LOGIN_USER}
 
diff --git a/server/autotest_server/__init__.py b/server/autotest_server/__init__.py
index c11af9c4..7af410aa 100644
--- a/server/autotest_server/__init__.py
+++ b/server/autotest_server/__init__.py
@@ -83,6 +83,8 @@ def _create_test_group_result(
             result["annotations"] = res["annotations"]
         elif "tags" in res:
             result["tags"] = res["tags"]
+        elif "extra_marks" in res:
+            result["extra_marks"] = res["extra_marks"]
         elif "overall_comment" in res:
             result["overall_comment"] = res["overall_comment"]
         else:
diff --git a/server/autotest_server/testers/ai/ai_tester.py b/server/autotest_server/testers/ai/ai_tester.py
index c3fbf67f..8ecf6e04 100644
--- a/server/autotest_server/testers/ai/ai_tester.py
+++ b/server/autotest_server/testers/ai/ai_tester.py
@@ -53,6 +53,7 @@ def __init__(
         super().__init__(specs, test_class, resource_settings=resource_settings)
         self.annotations = []
         self.overall_comments = []
+        self.tags = []
 
     def call_ai_feedback(self) -> dict:
         """
@@ -81,7 +82,17 @@ def call_ai_feedback(self) -> dict:
             return results
 
         submission_file = config.get("submission")
-        if self._term_in_file(submission_file):
+        try:
+            disallowed_term_in_file = self._term_in_file(submission_file)
+        except FileNotFoundError:
+            results[test_label] = {
+                "title": test_label,
+                "status": "error",
+                "message": f'Could not file submission file "{submission_file}"',
+            }
+            return results
+
+        if disallowed_term_in_file:
             results[test_label] = {
                 "title": test_label,
                 "status": "success",
@@ -96,15 +107,26 @@ def call_ai_feedback(self) -> dict:
         try:
             result = subprocess.run(cmd, capture_output=True, text=True, check=True, timeout=timeout, env=env)
             output = result.stdout
+
+            parsed = None
+            try:
+                parsed = json.loads(output)
+            except json.JSONDecodeError:
+                pass
+            if isinstance(parsed, dict):
+                if "tags" in parsed:
+                    tags = parsed["tags"]
+                    self.tags.extend(tags)
+                if "output" in parsed:
+                    output = parsed["output"]
+
             if output_mode == "overall_comment":
                 self.overall_comments.append(output)
                 results[test_label] = {"title": test_label, "status": "success"}
             elif output_mode == "annotations":
-                try:
-                    annotations_data = json.loads(output)
-                    annotations = annotations_data.get("annotations", annotations_data)
-                except json.JSONDecodeError as e:
-                    raise ValueError(f"Invalid JSON in output for {test_label}: {e}")
+                if parsed is None:
+                    raise ValueError(f"Unable to parse the output of '{output}'")
+                annotations = parsed.get("annotations", parsed)
                 self.annotations.extend(annotations)
                 results[test_label] = {"title": test_label, "status": "success"}
             elif output_mode == "message":
@@ -122,23 +144,20 @@ def _term_in_file(self, file_path: str) -> bool:
         term = "NO_EXTERNAL_AI_FEEDBACK"
         path = Path(file_path)
 
-        try:
-            if path.suffix.lower() == ".pdf":
-                with open(file_path, "rb") as f:
-                    reader = PyPDF2.PdfReader(f)
-                    for page in reader.pages:
-                        text = page.extract_text() or ""
-                        if term in text:
-                            return True
-                return False
-            else:
-                with open(file_path, "r", encoding="utf-8") as f:
-                    for line in f:
-                        if term in line:
-                            return True
-                return False
-        except FileNotFoundError:
-            return True
+        if path.suffix.lower() == ".pdf":
+            with open(file_path, "rb") as f:
+                reader = PyPDF2.PdfReader(f)
+                for page in reader.pages:
+                    text = page.extract_text() or ""
+                    if term in text:
+                        return True
+            return False
+        else:
+            with open(file_path, "r", encoding="utf-8") as f:
+                for line in f:
+                    if term in line:
+                        return True
+            return False
 
     @Tester.run_decorator
     def run(self) -> None:
@@ -157,3 +176,5 @@ def after_tester_run(self) -> None:
             print(self.test_class.format_annotations(self.annotations))
         if self.overall_comments:
             print(self.test_class.format_overall_comment(self.overall_comments, separator="\n\n"))
+        if self.tags:
+            print(self.test_class.format_tags(self.tags))
diff --git a/server/autotest_server/testers/haskell/haskell_tester.py b/server/autotest_server/testers/haskell/haskell_tester.py
index 48674fde..78010e53 100644
--- a/server/autotest_server/testers/haskell/haskell_tester.py
+++ b/server/autotest_server/testers/haskell/haskell_tester.py
@@ -7,6 +7,9 @@
 from ..tester import Tester, Test, TestError
 from ..specs import TestSpecs
 
+home = os.getenv("HOME")
+os.environ["PATH"] = f"{home}/.cabal/bin:{home}/.ghcup/bin:" + os.environ["PATH"]
+
 
 class HaskellTest(Test):
     def __init__(
diff --git a/server/autotest_server/testers/haskell/requirements.system b/server/autotest_server/testers/haskell/requirements.system
index 341699d1..7b493126 100755
--- a/server/autotest_server/testers/haskell/requirements.system
+++ b/server/autotest_server/testers/haskell/requirements.system
@@ -1,8 +1,15 @@
 #!/usr/bin/env bash
 
-if ! dpkg -l ghc cabal-install haskell-stack &> /dev/null; then
-  apt-get -y update
-  DEBIAN_FRONTEND=noninteractive apt-get install -y -o 'Dpkg::Options::=--force-confdef' -o 'Dpkg::Options::=--force-confold' ghc cabal-install haskell-stack
+apt-get -y update
+
+if ! dpkg -l ghc cabal-install &> /dev/null; then
+  DEBIAN_FRONTEND=noninteractive apt-get install -y -o 'Dpkg::Options::=--force-confdef' -o 'Dpkg::Options::=--force-confold' ghc cabal-install
 fi
 
-stack update
+if [ ! -x "$HOME/.ghcup/bin/ghcup" ] && [ ! -x "/usr/local/bin/stack" ]; then
+  BOOTSTRAP_HASKELL_NONINTERACTIVE=1 BOOTSTRAP_HASKELL_INSTALL_NO_STACK=1 curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
+  $HOME/.ghcup/bin/ghcup install stack recommended
+  if [ "$(id -u)" -eq 0 ]; then
+    cp $HOME/.ghcup/bin/stack /usr/local/bin/
+  fi
+fi
diff --git a/server/autotest_server/testers/haskell/setup.py b/server/autotest_server/testers/haskell/setup.py
index 6bfb446f..48e4d3f7 100644
--- a/server/autotest_server/testers/haskell/setup.py
+++ b/server/autotest_server/testers/haskell/setup.py
@@ -3,7 +3,10 @@
 import subprocess
 
 HASKELL_TEST_DEPS = ["tasty-discover", "tasty-quickcheck", "tasty-hunit"]
-STACK_RESOLVER = "lts-16.17"
+STACK_RESOLVER = "lts-21.21"
+
+home = os.getenv("HOME")
+os.environ["PATH"] = f"{home}/.cabal/bin:{home}/.ghcup/bin:" + os.environ["PATH"]
 
 
 def create_environment(_settings, _env_dir, default_env_dir):
@@ -16,22 +19,31 @@ def create_environment(_settings, _env_dir, default_env_dir):
 
 
 def install():
-    subprocess.run(
-        os.path.join(os.path.dirname(os.path.realpath(__file__)), "requirements.system"),
-        check=True,
-        capture_output=True,
-        text=True,
-    )
+    try:
+        subprocess.run(
+            os.path.join(os.path.dirname(os.path.realpath(__file__)), "requirements.system"),
+            check=True,
+            capture_output=True,
+            text=True,
+        )
+    except subprocess.CalledProcessError as e:
+        raise RuntimeError(f"Error executing Haskell requirements.system: {e}")
     resolver = STACK_RESOLVER
     cmd = ["stack", "build", "--resolver", resolver, "--system-ghc", *HASKELL_TEST_DEPS]
-    subprocess.run(cmd, check=True, capture_output=True)
-    subprocess.run(
-        os.path.join(os.path.dirname(os.path.realpath(__file__)), "stack_permissions.sh"),
-        check=True,
-        shell=True,
-        capture_output=True,
-        text=True,
-    )
+    try:
+        subprocess.run(cmd, check=True, capture_output=True)
+    except subprocess.CalledProcessError as e:
+        raise RuntimeError(f"Error running {cmd}: {e}")
+    try:
+        subprocess.run(
+            os.path.join(os.path.dirname(os.path.realpath(__file__)), "stack_permissions.sh"),
+            check=True,
+            shell=True,
+            capture_output=True,
+            text=True,
+        )
+    except subprocess.CalledProcessError as e:
+        raise RuntimeError(f"Error running Haskell stack_permissions.sh: {e}")
 
 
 def settings():
diff --git a/server/autotest_server/testers/haskell/stack_permissions.sh b/server/autotest_server/testers/haskell/stack_permissions.sh
index 22c3fd34..2bb5d2f3 100755
--- a/server/autotest_server/testers/haskell/stack_permissions.sh
+++ b/server/autotest_server/testers/haskell/stack_permissions.sh
@@ -2,4 +2,6 @@ echo "allow-different-user: true" >> $STACK_ROOT/config.yaml
 echo "recommend-stack-upgrade: false" >> $STACK_ROOT/config.yaml
 chmod a+w $STACK_ROOT/stack.sqlite3.pantry-write-lock
 chmod a+w $STACK_ROOT/global-project/.stack-work/stack.sqlite3.pantry-write-lock
-chmod a+w $STACK_ROOT/pantry/pantry.sqlite3.pantry-write-lock
\ No newline at end of file
+chmod a+w $STACK_ROOT/pantry/pantry.sqlite3.pantry-write-lock
+chmod a+r $WORKSPACE/.stack/config.yaml
+chmod a+r $WORKSPACE/.stack/global-project/stack.yaml
diff --git a/server/autotest_server/testers/jupyter/requirements.txt b/server/autotest_server/testers/jupyter/requirements.txt
index 7857feff..5c413cae 100644
--- a/server/autotest_server/testers/jupyter/requirements.txt
+++ b/server/autotest_server/testers/jupyter/requirements.txt
@@ -1,3 +1,3 @@
 pytest==7.1.2
-psycopg2-binary==2.9.10
+psycopg2-binary==2.9.11
 git+https://github.com/MarkUsProject/autotest-helpers.git#subdirectory=notebook_helper
diff --git a/server/autotest_server/testers/py/py_tester.py b/server/autotest_server/testers/py/py_tester.py
index 5af506ff..61ae13c7 100644
--- a/server/autotest_server/testers/py/py_tester.py
+++ b/server/autotest_server/testers/py/py_tester.py
@@ -5,6 +5,7 @@
 import pytest
 import sys
 from ..tester import Tester, Test
+import uuid
 from ..specs import TestSpecs
 
 
@@ -102,6 +103,7 @@ def __init__(self) -> None:
         self.results = {}
         self.tags = set()
         self.annotations = []
+        self.extra_marks = []
         self.overall_comments = []
 
     def pytest_configure(self, config):
@@ -118,6 +120,10 @@ def pytest_configure(self, config):
             "markers",
             "markus_message(text): indicate text that is displayed as part of the test output (even on success)",
         )
+        config.addinivalue_line(
+            "markers",
+            "markus_extra_marks(mark, description, unit): add extra marks with custom description",
+        )
 
     @pytest.hookimpl(hookwrapper=True, tryfirst=True)
     def pytest_runtest_makereport(self, item, call):
@@ -174,6 +180,15 @@ def _process_markers(self, item):
                 self.results[item.nodeid]["marks_total"] = marker.args[0]
             elif marker.name == "markus_marks_earned" and marker.args != [] and item.nodeid in self.results:
                 self.results[item.nodeid]["marks_earned"] = marker.args[0]
+            elif marker.name == "markus_extra_marks" and marker.args != [] and item.nodeid in self.results:
+                extra_mark = {
+                    "id": str(uuid.uuid4()),
+                    "mark": marker.args[0],
+                    "fn": item.nodeid,
+                    "description": marker.args[1],
+                    "unit": marker.args[2] if len(marker.args) > 2 else "points",
+                }
+                self.extra_marks.append(extra_mark)
 
     def pytest_collectreport(self, report):
         """
@@ -263,6 +278,7 @@ def __init__(
         """
         super().__init__(specs, test_class, resource_settings=resource_settings)
         self.annotations = []
+        self.extra_marks = []
         self.overall_comments = []
         self.tags = set()
 
@@ -307,6 +323,7 @@ def _run_pytest_tests(self, test_file: str) -> List[Dict]:
                 results.extend(plugin.results.values())
                 self.annotations = plugin.annotations
                 self.overall_comments = plugin.overall_comments
+                self.extra_marks = plugin.extra_marks
                 self.tags = plugin.tags
             finally:
                 sys.stdout = sys.__stdout__
@@ -344,3 +361,5 @@ def after_tester_run(self) -> None:
             print(self.test_class.format_tags(self.tags))
         if self.overall_comments:
             print(self.test_class.format_overall_comment(self.overall_comments, separator="\n\n"))
+        if self.extra_marks:
+            print(self.test_class.format_extra_marks(self.extra_marks))
diff --git a/server/autotest_server/testers/py/requirements.txt b/server/autotest_server/testers/py/requirements.txt
index 6c2622fc..9fe9dc8f 100644
--- a/server/autotest_server/testers/py/requirements.txt
+++ b/server/autotest_server/testers/py/requirements.txt
@@ -1,2 +1,2 @@
 pytest==7.1.2
-psycopg2-binary==2.9.10
+psycopg2-binary==2.9.11
diff --git a/server/autotest_server/testers/r/lib/r_tester_setup.R b/server/autotest_server/testers/r/lib/r_tester_setup.R
index 4aef4b00..f56775cc 100644
--- a/server/autotest_server/testers/r/lib/r_tester_setup.R
+++ b/server/autotest_server/testers/r/lib/r_tester_setup.R
@@ -38,7 +38,7 @@ install_dep <- function(row) {
   } else {
     remote_type <- NA_character_
   }
-  if (!('stringi' %in% rownames(installed.packages))) {
+  if (!('stringi' %in% rownames(installed.packages()))) {
     install.packages(name, configure.args="--disable-pkg-config")
   }
 
diff --git a/server/autotest_server/testers/tester.py b/server/autotest_server/testers/tester.py
index e581d58c..d34ee8c8 100644
--- a/server/autotest_server/testers/tester.py
+++ b/server/autotest_server/testers/tester.py
@@ -43,12 +43,7 @@ def get_total_points(self) -> int:
 
     @staticmethod
     def format_result(
-        test_name: str,
-        status: str,
-        output: str,
-        points_earned: int,
-        points_total: int,
-        time: Optional[int] = None,
+        test_name: str, status: str, output: str, points_earned: int, points_total: int, time: Optional[int] = None
     ) -> str:
         """
         Formats a test result.
@@ -115,6 +110,15 @@ def format_overall_comment(overall_comment_data: str | Iterable[str], separator:
             content = separator.join(overall_comment_data)
         return json.dumps({"overall_comment": content})
 
+    @staticmethod
+    def format_extra_marks(extra_marks: List[Dict[str, Any]]) -> str:
+        """
+        Formats extra marks data.
+        :param extra_marks: the contents of the extra marks
+        :return a json string representation of the extra marks data.
+        """
+        return json.dumps({"extra_marks": extra_marks})
+
     @staticmethod
     def format_tags(tag_data: Iterable[str | dict[str, str]]) -> str:
         """
@@ -141,11 +145,7 @@ def passed_with_bonus(self, points_bonus: int, message: str = "") -> str:
         """
         if points_bonus < 0:
             raise ValueError("The test bonus points must be >= 0")
-        result = self.format(
-            status=self.Status.PASS,
-            output=message,
-            points_earned=self.points_total + points_bonus,
-        )
+        result = self.format(status=self.Status.PASS, output=message, points_earned=self.points_total + points_bonus)
         return result
 
     def passed(self, message: str = "") -> str:
@@ -171,10 +171,7 @@ def partially_passed(self, points_earned: int, message: str) -> str:
         result = self.format(status=self.Status.PARTIAL, output=message, points_earned=points_earned)
         return result
 
-    def failed(
-        self,
-        message: str,
-    ) -> str:
+    def failed(self, message: str) -> str:
         """
         Fails this test with 0 points earned. If a feedback file is enabled, adds feedback to it.
         :param message: The failure message, will be shown as test output.
diff --git a/server/requirements.txt b/server/requirements.txt
index bae260c1..c5c98d5d 100644
--- a/server/requirements.txt
+++ b/server/requirements.txt
@@ -1,8 +1,7 @@
-rq==2.4.1
-click==8.1.8
-redis==6.2.0
-pyyaml==6.0.2
-jsonschema==4.25.0
-requests==2.32.4
-psycopg2-binary==2.9.10
-supervisor==4.2.5
+rq==2.6.0
+redis==7.1.0
+pyyaml==6.0.3
+jsonschema==4.25.1
+requests==2.32.5
+psycopg2-binary==2.9.11
+supervisor==4.3.0