fix[next]: use current working directory as default cache folder root (…

…#1744)

Change the root folder of the gt4py cache directory from the system temp
folder to the current working directory, which is more visible and also
avoids polluting shared filesystems in hpc clusters.

---------

Co-authored-by: Hannes Vogt <[email protected]>

src/gt4py/next/config.py

@@ -11,7 +11,6 @@
 import enum
 import os
 import pathlib
-import tempfile
 from typing import Final
 
 
@@ -51,37 +50,34 @@ def env_flag_to_bool(name: str, default: bool) -> bool:
             )
 
 
-_PREFIX: Final[str] = "GT4PY"
-
 #: Master debug flag
 #: Changes defaults for all the other options to be as helpful for debugging as possible.
 #: Does not override values set in environment variables.
-DEBUG: Final[bool] = env_flag_to_bool(f"{_PREFIX}_DEBUG", default=False)
+DEBUG: Final[bool] = env_flag_to_bool("GT4PY_DEBUG", default=False)
 
 
 #: Verbose flag for DSL compilation errors
 VERBOSE_EXCEPTIONS: bool = env_flag_to_bool(
-    f"{_PREFIX}_VERBOSE_EXCEPTIONS", default=True if DEBUG else False
+    "GT4PY_VERBOSE_EXCEPTIONS", default=True if DEBUG else False
 )
 
 
 #: Where generated code projects should be persisted.
 #: Only active if BUILD_CACHE_LIFETIME is set to PERSISTENT
 BUILD_CACHE_DIR: pathlib.Path = (
-    pathlib.Path(os.environ.get(f"{_PREFIX}_BUILD_CACHE_DIR", tempfile.gettempdir()))
-    / "gt4py_cache"
+    pathlib.Path(os.environ.get("GT4PY_BUILD_CACHE_DIR", pathlib.Path.cwd())) / ".gt4py_cache"
 )
 
 
 #: Whether generated code projects should be kept around between runs.
 #: - SESSION: generated code projects get destroyed when the interpreter shuts down
 #: - PERSISTENT: generated code projects are written to BUILD_CACHE_DIR and persist between runs
 BUILD_CACHE_LIFETIME: BuildCacheLifetime = BuildCacheLifetime[
-    os.environ.get(f"{_PREFIX}_BUILD_CACHE_LIFETIME", "persistent" if DEBUG else "session").upper()
+    os.environ.get("GT4PY_BUILD_CACHE_LIFETIME", "persistent" if DEBUG else "session").upper()
 ]
 
 #: Build type to be used when CMake is used to compile generated code.
 #: Might have no effect when CMake is not used as part of the toolchain.
 CMAKE_BUILD_TYPE: CMakeBuildType = CMakeBuildType[
-    os.environ.get(f"{_PREFIX}_CMAKE_BUILD_TYPE", "debug" if DEBUG else "release").upper()
+    os.environ.get("GT4PY_CMAKE_BUILD_TYPE", "debug" if DEBUG else "release").upper()
 ]