Combine studio setup fixes: frontend caching, venv isolation, Windows CPU support

studio/backend/colab.py

@@ -9,6 +9,31 @@
 from pathlib import Path
 import sys
 
+
+def _bootstrap_studio_venv() -> None:
+    """Expose the Studio venv's site-packages to the current interpreter.
+
+    On Colab, notebook cells run outside the venv subshell. Instead of
+    installing the full stack into system Python, we prepend the venv's
+    site-packages so that packages like structlog, fastapi, etc. are
+    importable from notebook cells and take priority over system copies.
+    """
+    venv_lib = Path.home() / ".unsloth" / "studio" / ".venv" / "lib"
+    if not venv_lib.exists():
+        import warnings
+        warnings.warn(
+            f"Studio venv not found at {venv_lib.parent} -- run 'unsloth studio setup' first",
+            stacklevel=2,
+        )
+        return
+    for sp in venv_lib.glob("python*/site-packages"):
+        sp_str = str(sp)
+        if sp_str not in sys.path:
+            sys.path.insert(0, sp_str)
+
+
+_bootstrap_studio_venv()
+
 # Add backend to path early so local modules like loggers can be imported
 backend_path = str(Path(__file__).parent)
 if backend_path not in sys.path:

studio/backend/core/export/worker.py

@@ -40,59 +40,25 @@ def _activate_transformers_version(model_name: str) -> None:
     if backend_path not in sys.path:
         sys.path.insert(0, backend_path)
 
-    from utils.transformers_version import needs_transformers_5, _resolve_base_model
+    from utils.transformers_version import (
+        needs_transformers_5,
+        _resolve_base_model,
+        _ensure_venv_t5_exists,
+        _VENV_T5_DIR,
+    )
 
     resolved = _resolve_base_model(model_name)
     if needs_transformers_5(resolved):
-        venv_t5 = os.path.join(
-            os.path.expanduser("~"), ".unsloth", "studio", ".venv_t5"
-        )
-        if os.path.isdir(venv_t5):
-            sys.path.insert(0, venv_t5)
-            logger.info("Activated transformers 5.x from %s", venv_t5)
-        else:
-            # Fallback: pip install at runtime (slower, ~10-15s)
-            logger.warning(".venv_t5 not found at %s — installing at runtime", venv_t5)
-            import subprocess as sp
-
-            os.makedirs(venv_t5, exist_ok = True)
-            r1 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "transformers==5.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
+        if not _ensure_venv_t5_exists():
+            raise RuntimeError(
+                f"Cannot activate transformers 5.x: .venv_t5 missing at {_VENV_T5_DIR}"
             )
-            r2 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "huggingface_hub==1.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
-            )
-            if r1.returncode != 0 or r2.returncode != 0:
-                raise RuntimeError(
-                    f"Failed to install transformers 5.x into {venv_t5}. "
-                    f"pip returncode: transformers={r1.returncode}, huggingface_hub={r2.returncode}"
-                )
-            sys.path.insert(0, venv_t5)
+        if _VENV_T5_DIR not in sys.path:
+            sys.path.insert(0, _VENV_T5_DIR)
+        logger.info("Activated transformers 5.x from %s", _VENV_T5_DIR)
         # Propagate to child subprocesses (e.g. GGUF converter)
         _pp = os.environ.get("PYTHONPATH", "")
-        os.environ["PYTHONPATH"] = venv_t5 + (os.pathsep + _pp if _pp else "")
+        os.environ["PYTHONPATH"] = _VENV_T5_DIR + (os.pathsep + _pp if _pp else "")
     else:
         logger.info("Using default transformers (4.57.x) for %s", model_name)
 

studio/backend/core/inference/worker.py

@@ -42,59 +42,25 @@ def _activate_transformers_version(model_name: str) -> None:
     if backend_path not in sys.path:
         sys.path.insert(0, backend_path)
 
-    from utils.transformers_version import needs_transformers_5, _resolve_base_model
+    from utils.transformers_version import (
+        needs_transformers_5,
+        _resolve_base_model,
+        _ensure_venv_t5_exists,
+        _VENV_T5_DIR,
+    )
 
     resolved = _resolve_base_model(model_name)
     if needs_transformers_5(resolved):
-        venv_t5 = os.path.join(
-            os.path.expanduser("~"), ".unsloth", "studio", ".venv_t5"
-        )
-        if os.path.isdir(venv_t5):
-            sys.path.insert(0, venv_t5)
-            logger.info("Activated transformers 5.x from %s", venv_t5)
-        else:
-            # Fallback: pip install at runtime (slower, ~10-15s)
-            logger.warning(".venv_t5 not found at %s — installing at runtime", venv_t5)
-            import subprocess as sp
-
-            os.makedirs(venv_t5, exist_ok = True)
-            r1 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "transformers==5.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
+        if not _ensure_venv_t5_exists():
+            raise RuntimeError(
+                f"Cannot activate transformers 5.x: .venv_t5 missing at {_VENV_T5_DIR}"
             )
-            r2 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "huggingface_hub==1.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
-            )
-            if r1.returncode != 0 or r2.returncode != 0:
-                raise RuntimeError(
-                    f"Failed to install transformers 5.x into {venv_t5}. "
-                    f"pip returncode: transformers={r1.returncode}, huggingface_hub={r2.returncode}"
-                )
-            sys.path.insert(0, venv_t5)
+        if _VENV_T5_DIR not in sys.path:
+            sys.path.insert(0, _VENV_T5_DIR)
+        logger.info("Activated transformers 5.x from %s", _VENV_T5_DIR)
         # Propagate to child subprocesses (e.g. GGUF converter)
         _pp = os.environ.get("PYTHONPATH", "")
-        os.environ["PYTHONPATH"] = venv_t5 + (os.pathsep + _pp if _pp else "")
+        os.environ["PYTHONPATH"] = _VENV_T5_DIR + (os.pathsep + _pp if _pp else "")
     else:
         logger.info("Using default transformers (4.57.x) for %s", model_name)
 

studio/backend/core/training/worker.py

@@ -36,59 +36,25 @@ def _activate_transformers_version(model_name: str) -> None:
     if backend_path not in sys.path:
         sys.path.insert(0, backend_path)
 
-    from utils.transformers_version import needs_transformers_5, _resolve_base_model
+    from utils.transformers_version import (
+        needs_transformers_5,
+        _resolve_base_model,
+        _ensure_venv_t5_exists,
+        _VENV_T5_DIR,
+    )
 
     resolved = _resolve_base_model(model_name)
     if needs_transformers_5(resolved):
-        venv_t5 = os.path.join(
-            os.path.expanduser("~"), ".unsloth", "studio", ".venv_t5"
-        )
-        if os.path.isdir(venv_t5):
-            sys.path.insert(0, venv_t5)
-            logger.info("Activated transformers 5.x from %s", venv_t5)
-        else:
-            # Fallback: pip install at runtime (slower, ~10-15s)
-            logger.warning(".venv_t5 not found at %s — installing at runtime", venv_t5)
-            import subprocess as sp
-
-            os.makedirs(venv_t5, exist_ok = True)
-            r1 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "transformers==5.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
+        if not _ensure_venv_t5_exists():
+            raise RuntimeError(
+                f"Cannot activate transformers 5.x: .venv_t5 missing at {_VENV_T5_DIR}"
             )
-            r2 = sp.run(
-                [
-                    sys.executable,
-                    "-m",
-                    "pip",
-                    "install",
-                    "--target",
-                    venv_t5,
-                    "--no-deps",
-                    "huggingface_hub==1.3.0",
-                ],
-                stdout = sp.PIPE,
-                stderr = sp.STDOUT,
-            )
-            if r1.returncode != 0 or r2.returncode != 0:
-                raise RuntimeError(
-                    f"Failed to install transformers 5.x into {venv_t5}. "
-                    f"pip returncode: transformers={r1.returncode}, huggingface_hub={r2.returncode}"
-                )
-            sys.path.insert(0, venv_t5)
+        if _VENV_T5_DIR not in sys.path:
+            sys.path.insert(0, _VENV_T5_DIR)
+        logger.info("Activated transformers 5.x from %s", _VENV_T5_DIR)
         # Propagate to child subprocesses (e.g. GGUF converter)
         _pp = os.environ.get("PYTHONPATH", "")
-        os.environ["PYTHONPATH"] = venv_t5 + (os.pathsep + _pp if _pp else "")
+        os.environ["PYTHONPATH"] = _VENV_T5_DIR + (os.pathsep + _pp if _pp else "")
     else:
         logger.info("Using default transformers (4.57.x) for %s", model_name)
 

studio/backend/requirements/extras-no-deps.txt

@@ -11,4 +11,4 @@ git+https://github.com/meta-pytorch/OpenEnv.git
 # executorch>=1.0.1               # 41.5 MB - no imports in unsloth/zoo/studio
 torch-c-dlpack-ext
 sentence_transformers==5.2.0
-transformers==4.57.1
+transformers==4.57.6

studio/backend/requirements/single-env/constraints.txt

@@ -1,6 +1,6 @@
 # Single-env pins for unsloth + studio + data-designer
 # Keep compatible with unsloth transformers bounds.
-transformers==4.57.1
+transformers==4.57.6
 trl==0.23.1
 huggingface-hub==0.36.2