diff --git a/.github/unittest/linux_libs/scripts_gym/10_nvidia.json b/.github/unittest/linux_libs/scripts_gym/10_nvidia.json
new file mode 100644
index 00000000000..576b540c387
--- /dev/null
+++ b/.github/unittest/linux_libs/scripts_gym/10_nvidia.json
@@ -0,0 +1,6 @@
+{
+    "file_format_version" : "1.0.0",
+    "ICD" : {
+        "library_path" : "libEGL_nvidia.so.0"
+    }
+} 
diff --git a/.github/unittest/linux_libs/scripts_gym/run_test.sh b/.github/unittest/linux_libs/scripts_gym/run_test.sh
index ff2f298c9d2..d1e2967325f 100755
--- a/.github/unittest/linux_libs/scripts_gym/run_test.sh
+++ b/.github/unittest/linux_libs/scripts_gym/run_test.sh
@@ -18,12 +18,22 @@ lib_dir="${env_dir}/lib"
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$lib_dir
 export MKL_THREADING_LAYER=GNU
 
+# Start Xvfb with specific OpenGL configuration
+export DISPLAY=:99
+Xvfb :99 -screen 0 1400x900x24 -ac +extension GLX +render -noreset > /dev/null 2>&1 &
+sleep 3  # Give Xvfb time to start
+
+# Verify OpenGL/EGL setup
+glxinfo -B || true
+echo "EGL_PLATFORM=$EGL_PLATFORM"
+echo "MUJOCO_GL=$MUJOCO_GL"
+echo "PYOPENGL_PLATFORM=$PYOPENGL_PLATFORM"
+
+# Run the tests
 python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test.py -v --durations 200
 python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test_deps.py -v --durations 200 -k 'test_gym'
 
 unset LD_PRELOAD
-export DISPLAY=:99
-Xvfb :99 -screen 0 1400x900x24 > /dev/null 2>&1 &
 python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/test_libs.py --instafail -v --durations 200 -k "gym and not isaac" --error-for-skips --mp_fork
 coverage combine
 coverage xml -i
diff --git a/.github/unittest/linux_libs/scripts_gym/setup_env.sh b/.github/unittest/linux_libs/scripts_gym/setup_env.sh
index aade606ba16..417ee8fef69 100755
--- a/.github/unittest/linux_libs/scripts_gym/setup_env.sh
+++ b/.github/unittest/linux_libs/scripts_gym/setup_env.sh
@@ -5,14 +5,28 @@
 #
 # Do not install PyTorch and torchvision here, otherwise they also get cached.
 
+unset PYTORCH_VERSION
+# For unittest, nightly PyTorch is used as the following section,
+# so no need to set PYTORCH_VERSION.
+# In fact, keeping PYTORCH_VERSION forces us to hardcode PyTorch version in config.
+apt-get update && apt-get install -y \
+    git wget gcc g++ \
+    libglfw3 libgl1-mesa-glx libosmesa6 libglew-dev \
+    libglvnd0 libgl1 libglx0 libegl1 libgles2 \
+    xvfb libegl-dev libx11-dev freeglut3-dev \
+    mesa-utils mesa-common-dev \
+    libsdl2-dev libsdl2-2.0-0
+
 set -e
+set -v
 
 this_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-# Avoid error: "fatal: unsafe repository"
-apt-get update && apt-get install -y git wget gcc g++
-apt-get install -y libglfw3 libgl1-mesa-glx libosmesa6 libglew-dev libsdl2-dev libsdl2-2.0-0
-apt-get install -y libglvnd0 libgl1 libglx0 libegl1 libgles2 xvfb libegl-dev libx11-dev freeglut3-dev
 
+# Setup EGL
+mkdir -p /usr/share/glvnd/egl_vendor.d
+cp $this_dir/10_nvidia.json /usr/share/glvnd/egl_vendor.d/10_nvidia.json
+
+# Avoid error: "fatal: unsafe repository"
 git config --global --add safe.directory '*'
 root_dir="$(git rev-parse --show-toplevel)"
 conda_dir="${root_dir}/conda"
@@ -79,13 +93,15 @@ conda env config vars set \
   SDL_VIDEODRIVER=dummy \
   DISPLAY=:99 \
   PYOPENGL_PLATFORM=egl \
-  LD_PRELOAD=$glew_path \
+  __GLX_VENDOR_LIBRARY_NAME=nvidia \
+  MESA_GL_VERSION_OVERRIDE=3.3 \
+  EGL_PLATFORM=x11 \
+  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libGLEW.so:/usr/lib/x86_64-linux-gnu/libGL.so \
   NVIDIA_PATH=/usr/src/nvidia-470.63.01 \
   MUJOCO_PY_MJKEY_PATH=${root_dir}/mujoco-py/mujoco_py/binaries/mjkey.txt \
   MUJOCO_PY_MUJOCO_PATH=${root_dir}/mujoco-py/mujoco_py/binaries/linux/mujoco210 \
-  LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/pytorch/rl/mujoco-py/mujoco_py/binaries/linux/mujoco210/bin
+  LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/pytorch/rl/mujoco-py/mujoco_py/binaries/linux/mujoco210/bin \
   TOKENIZERS_PARALLELISM=true
-#  LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/circleci/project/mujoco-py/mujoco_py/binaries/linux/mujoco210/bin
 
 # make env variables apparent
 conda deactivate && conda activate "${env_dir}"
diff --git a/.github/unittest/linux_olddeps/scripts_gym_0_13/environment.yml b/.github/unittest/linux_olddeps/scripts_gym_0_13/environment.yml
index 61726cae9b7..b722944bc1e 100644
--- a/.github/unittest/linux_olddeps/scripts_gym_0_13/environment.yml
+++ b/.github/unittest/linux_olddeps/scripts_gym_0_13/environment.yml
@@ -24,6 +24,7 @@ dependencies:
     - mujoco
     - patchelf
     - pyopengl==3.1.4
+    - pyglet<1.5.0
     - ray
     - av
     - h5py
diff --git a/.github/unittest/linux_olddeps/scripts_gym_0_13/run_test.sh b/.github/unittest/linux_olddeps/scripts_gym_0_13/run_test.sh
index 7622c769aae..ebca125d32f 100755
--- a/.github/unittest/linux_olddeps/scripts_gym_0_13/run_test.sh
+++ b/.github/unittest/linux_olddeps/scripts_gym_0_13/run_test.sh
@@ -22,13 +22,20 @@ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/pytorch/rl/mujoco-py/mujoco_py/binaries
 export MKL_THREADING_LAYER=GNU
 export BATCHED_PIPE_TIMEOUT=60
 
-python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test.py -v --durations 200
-python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test_deps.py -v --durations 200 -k 'test_gym'
-
+# Start Xvfb with specific OpenGL configuration
 export DISPLAY=:99
 Xvfb :99 -screen 0 1400x900x24 > /dev/null 2>&1 &
+sleep 3  # Give Xvfb time to start
+
+# Verify OpenGL setup
+glxinfo -B || true
+echo "MUJOCO_GL=$MUJOCO_GL"
+echo "PYOPENGL_PLATFORM=$PYOPENGL_PLATFORM"
+
+python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test.py -v --durations 200
+python .github/unittest/helpers/coverage_run_parallel.py -m pytest test/smoke_test_deps.py -v --durations 200 -k 'test_gym'
 
-CKPT_BACKEND=torch MUJOCO_GL=egl python .github/unittest/helpers/coverage_run_parallel.py -m pytest \
+MUJOCO_GL=osmesa python .github/unittest/helpers/coverage_run_parallel.py -m pytest \
     --instafail -v \
     --durations 200 \
     --ignore test/test_distributed.py \
diff --git a/.github/unittest/linux_olddeps/scripts_gym_0_13/setup_env.sh b/.github/unittest/linux_olddeps/scripts_gym_0_13/setup_env.sh
index 0ab83d4b042..0a1323bcdd2 100755
--- a/.github/unittest/linux_olddeps/scripts_gym_0_13/setup_env.sh
+++ b/.github/unittest/linux_olddeps/scripts_gym_0_13/setup_env.sh
@@ -8,27 +8,63 @@
 set -e
 set -v
 
-this_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-
-apt-get update && apt-get upgrade -y
-printf "* Installing vim - git - wget\n"
-apt-get install -y vim git wget
+# Make apt-get non-interactive
+export DEBIAN_FRONTEND=noninteractive
+# Pre-configure timezone data
+ln -fs /usr/share/zoneinfo/UTC /etc/localtime
+echo "UTC" > /etc/timezone
 
-printf "* Installing glfw - glew - osmesa part 1\n"
-apt-get install -y libglvnd0 libgl1 libglx0 libegl1 libgles2 xvfb libx11-dev libegl-dev
+this_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 
-#printf "* Installing glfw - glew - osmesa part 2\n"
-#apt-get install -y libglfw3 libgl1-mesa-glx libosmesa6 libglew-dev libsdl2-dev libsdl2-2.0-0
+# Add NVIDIA repository for drivers
+apt-get update && apt-get install -y --no-install-recommends \
+    software-properties-common \
+    wget \
+    ca-certificates
+
+# Install basic build tools first
+apt-get install -y vim git wget build-essential
+
+# Install system libraries to fix version conflicts
+apt-get install -y --no-install-recommends \
+    libffi7 \
+    libffi-dev \
+    libtinfo6 \
+    libtinfo-dev \
+    libncurses5-dev \
+    libncursesw5-dev
+
+# Install OpenGL packages with focus on OSMesa
+apt-get install -y --no-install-recommends \
+    libosmesa6-dev \
+    libgl1-mesa-dev \
+    libgl1-mesa-glx \
+    libglew-dev \
+    libglfw3-dev \
+    libglvnd0 \
+    libgl1 \
+    libglx0 \
+    libegl1 \
+    libgles2 \
+    xvfb \
+    mesa-utils \
+    mesa-common-dev \
+    libglu1-mesa-dev \
+    libsdl2-dev \
+    libsdl2-2.0-0 \
+    pkg-config
 
 if [ "${CU_VERSION:-}" == cpu ] ; then
-  # solves version `GLIBCXX_3.4.29' not found for tensorboard
-#    apt-get install -y gcc-4.9
   apt-get upgrade -y libstdc++6
   apt-get dist-upgrade -y
 else
   apt-get install -y g++ gcc
 fi
 
+# Remove conflicting libraries from conda environment if they exist
+rm -f "${env_dir}/lib/libtinfo.so"* || true
+rm -f "${env_dir}/lib/libffi.so"* || true
+
 git config --global --add safe.directory '*'
 root_dir="$(git rev-parse --show-toplevel)"
 conda_dir="${root_dir}/conda"
@@ -93,19 +129,20 @@ printf "* Installing dependencies (except PyTorch)\n"
 echo "  - python=${PYTHON_VERSION}" >> "${this_dir}/environment.yml"
 cat "${this_dir}/environment.yml"
 
-export MUJOCO_GL=egl
+# Use OSMesa for rendering
+export MUJOCO_GL=osmesa
 conda env config vars set \
   MAX_IDLE_COUNT=1000 \
-  MUJOCO_GL=egl \
+  MUJOCO_GL=osmesa \
   SDL_VIDEODRIVER=dummy \
-  DISPLAY=unix:0.0 \
-  PYOPENGL_PLATFORM=egl \
-  LD_PRELOAD=$glew_path \
-  NVIDIA_PATH=/usr/src/nvidia-470.63.01 \
+  DISPLAY=:99 \
+  PYOPENGL_PLATFORM=osmesa \
+  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libOSMesa.so.6:/usr/lib/x86_64-linux-gnu/libGL.so \
   MUJOCO_PY_MJKEY_PATH=${root_dir}/mujoco-py/mujoco_py/binaries/mjkey.txt \
   MUJOCO_PY_MUJOCO_PATH=${root_dir}/mujoco-py/mujoco_py/binaries/linux/mujoco210 \
-  LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/circleci/project/mujoco-py/mujoco_py/binaries/linux/mujoco210/bin \
-  TOKENIZERS_PARALLELISM=true
+  LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu:$LD_LIBRARY_PATH:/home/circleci/project/mujoco-py/mujoco_py/binaries/linux/mujoco210/bin \
+  TOKENIZERS_PARALLELISM=true \
+  PYGLET_GRAPHICS=opengl3
 
 # make env variables apparent
 conda deactivate && conda activate "${env_dir}"
diff --git a/test/_utils_internal.py b/test/_utils_internal.py
index 6ae85cfaf20..443472a9286 100644
--- a/test/_utils_internal.py
+++ b/test/_utils_internal.py
@@ -182,7 +182,7 @@ def get_available_devices():
 def get_default_devices():
     num_cuda = torch.cuda.device_count()
     if num_cuda == 0:
-        # if torch.mps.is_available():
+        # if getattr(torch.mps, "is_available", lambda: False)():
         #     return [torch.device("mps:0")]
         return [torch.device("cpu")]
     elif num_cuda == 1:
diff --git a/test/test_collector.py b/test/test_collector.py
index fab2e04bb1d..0c9a53bb9de 100644
--- a/test/test_collector.py
+++ b/test/test_collector.py
@@ -1070,7 +1070,7 @@ def test_no_deepcopy_policy(self, collector_type):
         shared_device = torch.device("cpu")
         if torch.cuda.is_available():
             original_device = torch.device("cuda:0")
-        elif torch.mps.is_available():
+        elif getattr(torch.mps, "is_available", lambda: False)():
             original_device = torch.device("mps")
         else:
             pytest.skip("No GPU or MPS device")
@@ -2614,7 +2614,8 @@ def test_multi_collector_consistency(
 
 
 @pytest.mark.skipif(
-    not torch.cuda.is_available() and not torch.mps.is_available(),
+    not torch.cuda.is_available()
+    and not getattr(torch.mps, "is_available", lambda: False)(),
     reason="No casting if no cuda",
 )
 class TestUpdateParams:
diff --git a/torchrl/data/replay_buffers/utils.py b/torchrl/data/replay_buffers/utils.py
index 97c62bf9707..ee5fa5736dc 100644
--- a/torchrl/data/replay_buffers/utils.py
+++ b/torchrl/data/replay_buffers/utils.py
@@ -1036,6 +1036,6 @@ def tree_iter(pytree):  # noqa: F811
 def _auto_device() -> torch.device:
     if torch.cuda.is_available():
         return torch.device("cuda:0")
-    elif torch.mps.is_available():
+    elif getattr(torch.mps, "is_available", lambda: False)():
         return torch.device("mps:0")
     return torch.device("cpu")