diff --git a/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/Dockerfile b/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/Dockerfile
index a226cb27fd..35e49c753f 100644
--- a/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/Dockerfile
+++ b/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/Dockerfile
@@ -1,7 +1,11 @@
 FROM mcr.microsoft.com/azureml/openmpi5.0-cuda12.8-ubuntu24.04:{{latest-image-tag}}
 
 USER root
-WORKDIR /root
+# Editable sources live under /opt so AML/Singularity jobs (uid 9000) can
+# read them. /root is mode 700 and would make `import slime`, the slime
+# train.py entrypoint, and the Megatron-LM editable install unreachable
+# from a non-root job user.
+WORKDIR /opt
 
 ARG SLIME_COMMIT=9b50665190d70cefcc9cc42e5994ad4de5f0cd88
 ARG PATCH_VERSION=latest
@@ -14,7 +18,7 @@ ENV DEBIAN_FRONTEND=noninteractive
 ENV PIP_NO_CACHE_DIR=1
 ENV PYTHONUNBUFFERED=1
 ENV MAX_JOBS=1
-ENV PYTHONPATH=/root/Megatron-LM:${PYTHONPATH}
+ENV PYTHONPATH=/opt/Megatron-LM:${PYTHONPATH}
 
 RUN set -eux; \
     find /etc/apt -type f \( -name '*.list' -o -name '*.sources' \) \
@@ -47,8 +51,8 @@ RUN python -m pip install --no-cache-dir \
         flash-linear-attention==0.4.1 \
         tilelang -f https://tile-ai.github.io/whl/nightly/cu128/
 
-RUN git clone https://github.com/THUDM/slime.git /root/slime && \
-    cd /root/slime && \
+RUN git clone https://github.com/THUDM/slime.git /opt/slime && \
+    cd /opt/slime && \
     git checkout ${SLIME_COMMIT}
 
 RUN NVCC_APPEND_FLAGS="--threads 1" \
@@ -57,10 +61,10 @@ RUN NVCC_APPEND_FLAGS="--threads 1" \
         --config-settings "--build-option=--cpp_ext --cuda_ext --parallel 1" \
         git+https://github.com/NVIDIA/apex.git@10417aceddd7d5d05d7cbf7b0fc2daad1105f8b4
 
-RUN git clone https://github.com/NVIDIA/Megatron-LM.git --recursive /root/Megatron-LM && \
-    cd /root/Megatron-LM && \
+RUN git clone https://github.com/NVIDIA/Megatron-LM.git --recursive /opt/Megatron-LM && \
+    cd /opt/Megatron-LM && \
     git checkout ${MEGATRON_COMMIT} && \
-    git apply /root/slime/docker/patch/${PATCH_VERSION}/megatron.patch --3way && \
+    git apply /opt/slime/docker/patch/${PATCH_VERSION}/megatron.patch --3way && \
     if grep -R -n '^<<<<<<< ' .; then \
         echo "Megatron patch failed to apply cleanly." && \
         exit 1; \
@@ -99,12 +103,23 @@ RUN LOG4J_VERSION=${LOG4J_VERSION} \
     python /tmp/patch_ray_log4j.py && \
     rm /tmp/patch_ray_log4j.py
 
-RUN cd /root/slime && \
+RUN cd /opt/slime && \
     python -m pip install --no-cache-dir -e . --no-deps
 
-RUN cd /root/slime/slime/backends/megatron_utils/kernels/int4_qat && \
+RUN cd /opt/slime/slime/backends/megatron_utils/kernels/int4_qat && \
     python -m pip install --no-cache-dir . --no-build-isolation
 
+# AML/Singularity jobs run as uid 9000 (aiscuser). Explicitly grant
+# world read + traverse on the editable slime and Megatron-LM trees so
+# `import slime`, `python /opt/slime/train.py`, and the PYTHONPATH-based
+# Megatron-LM import all succeed without requiring `--user root`.
+RUN chmod -R a+rX /opt/slime /opt/Megatron-LM
+
 COPY smoke_test.py /tmp/smoke_test.py
 RUN python /tmp/smoke_test.py && \
-    rm /tmp/smoke_test.py
+    echo 'import importlib.util' > /tmp/slime_nonroot_check.py && \
+    echo 'import slime' >> /tmp/slime_nonroot_check.py && \
+    echo 'assert importlib.util.find_spec("slime") is not None' >> /tmp/slime_nonroot_check.py && \
+    chmod a+r /tmp/slime_nonroot_check.py && \
+    runuser -u nobody -- python /tmp/slime_nonroot_check.py && \
+    rm /tmp/smoke_test.py /tmp/slime_nonroot_check.py
diff --git a/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/smoke_test.py b/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/smoke_test.py
index d5da6f87f9..abcc69eefe 100644
--- a/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/smoke_test.py
+++ b/assets/training/finetune_acft_hf_nlp/environments/slime-pytorch-2.9-cuda12.8/context/smoke_test.py
@@ -3,9 +3,9 @@
 
 """Smoke-test the slime curated environment image."""
 
+import importlib.util
 import pathlib
 import zipfile
-
 from packaging.version import Version
 import PIL
 import ray
@@ -16,6 +16,7 @@
 
 LOG4J_ARTIFACTS = ("log4j-api", "log4j-core", "log4j-slf4j-impl")
 RAY_DIST_NAMES = ("ray_dist.jar", "ray__dist.jar")
+EXPECTED_SLIME_ROOT = pathlib.Path("/opt/slime")
 
 
 def find_ray_dist() -> pathlib.Path:
@@ -31,12 +32,60 @@ def find_ray_dist() -> pathlib.Path:
     return matches[0]
 
 
+def assert_slime_resolves_under_expected_root() -> None:
+    """Verify slime resolves to the readable editable source tree."""
+    spec = importlib.util.find_spec("slime")
+    assert spec is not None, "importlib cannot find slime"
+
+    paths: list[pathlib.Path] = []
+    slime_file = getattr(slime, "__file__", None)
+    if slime_file:
+        paths.append(pathlib.Path(slime_file).resolve())
+    if spec.origin and spec.origin != "namespace":
+        paths.append(pathlib.Path(spec.origin).resolve())
+    for location in spec.submodule_search_locations or ():
+        paths.append(pathlib.Path(location).resolve())
+    for location in getattr(slime, "__path__", ()):
+        paths.append(pathlib.Path(location).resolve())
+
+    assert paths, "slime imported but no source paths were discoverable"
+    assert any(
+        path == EXPECTED_SLIME_ROOT or EXPECTED_SLIME_ROOT in path.parents
+        for path in paths
+    ), f"slime resolved at {paths}, expected under {EXPECTED_SLIME_ROOT}"
+
+
+def assert_world_accessible(path: pathlib.Path) -> None:
+    """Verify a file/tree is readable by the non-root AML job user."""
+    assert path.exists(), f"missing {path}"
+    mode = path.stat().st_mode & 0o777
+    assert mode & 0o004, f"{path} not world-readable (mode={oct(mode)})"
+    if path.is_dir():
+        assert mode & 0o001, f"{path} not world-traversable (mode={oct(mode)})"
+
+
 assert torch.cuda.is_available() or torch.version.cuda
 assert torch.__version__.startswith("2.9.1")
 assert Version(PIL.__version__) >= Version("12.2.0")
 assert sglang
 assert slime
 
+# AML/Singularity jobs run as uid 9000 (aiscuser); /root is mode 700 so
+# slime must be editable-installed from a non-/root location. Pin the
+# expected location and verify world read+traverse on key files.
+assert_slime_resolves_under_expected_root()
+for path in (
+    EXPECTED_SLIME_ROOT,
+    EXPECTED_SLIME_ROOT / "train.py",
+    EXPECTED_SLIME_ROOT / "slime",
+    pathlib.Path("/opt/Megatron-LM"),
+):
+    assert_world_accessible(path)
+
+slime_init = EXPECTED_SLIME_ROOT / "slime" / "__init__.py"
+if slime_init.exists():
+    assert_world_accessible(slime_init)
+
 ray_dist = find_ray_dist()
 for artifact in LOG4J_ARTIFACTS:
     properties_name = f"META-INF/maven/org.apache.logging.log4j/{artifact}/pom.properties"