fix(template): keep the uv cache off /tmp during image builds

Co-Authored-By: mish@e2b.dev <mish@e2b.dev>

Author: devin-ai-integration[bot]

template/charts/pyproject.toml

@@ -23,7 +23,7 @@ module-name = ["e2b_charts"]
 module-root = ""
 
 [build-system]
-requires = ["uv_build>=0.10.0,<0.11.0"]
+requires = ["uv_build>=0.13.4,<0.14.0"]
 build-backend = "uv_build"
 
 [tool.ruff.lint]

template/template.py

@@ -1,12 +1,19 @@
 from e2b import ReadyCmd, Template, wait_for_url
 
 
-# `--no-editable` builds `charts` (via uv's built-in `uv_build` backend) instead
+# The cache lives on the image disk, not /tmp (which `--no-cache` would use and
+# which is too small for the kernel packages), and is removed in the same step.
+# `--no-editable` builds `charts` with uv's built-in `uv_build` backend instead
 # of linking the copied sources.
-UV_SYNC_FLAGS = (
-    "--locked --no-dev --no-editable --compile-bytecode --no-cache"
-    " --no-python-downloads"
-)
+UV_CACHE_DIR = "/root/.cache/uv"
+
+
+def uv_sync(project: str, flags: str = "") -> str:
+    return (
+        f"UV_CACHE_DIR={UV_CACHE_DIR} uv sync --project {project} --locked --no-dev"
+        f" --no-editable --compile-bytecode --no-python-downloads{flags}"
+        f" && rm -rf {UV_CACHE_DIR}"
+    )
 
 
 def make_template(
@@ -62,9 +69,11 @@ def make_template(
         .copy(["pyproject.toml", "uv.lock"], ".python-env/")
         .copy("charts", ".python-env/charts")
         .run_cmd(
-            "UV_PROJECT_ENVIRONMENT=/usr/local uv sync --project .python-env"
-            f" {UV_SYNC_FLAGS} --inexact"
-            + (" --group bash" if "bash" in enabled_kernels else "")
+            "UV_PROJECT_ENVIRONMENT=/usr/local "
+            + uv_sync(
+                ".python-env",
+                " --inexact" + (" --group bash" if "bash" in enabled_kernels else ""),
+            )
         )
     )
 
@@ -110,7 +119,7 @@ def make_template(
     template = (
         template
         # Create server virtual environment
-        .copy("server", ".server").run_cmd(f"uv sync --project .server {UV_SYNC_FLAGS}")
+        .copy("server", ".server").run_cmd(uv_sync(".server"))
     )
 
     # Copy configuration files