Lazy setuptools imports

pytensor/link/c/cmodule.py

@@ -26,19 +26,12 @@ from pathlib import Path
 from typing import TYPE_CHECKING, Protocol, cast
 
 import numpy as np
-from setuptools._distutils.sysconfig import (
-    get_config_h_filename,
-    get_config_var,
-    get_python_inc,
-    get_python_lib,
-)
 
 # we will abuse the lockfile mechanism when reading and writing the registry
 from pytensor.compile.compilelock import lock_ctx
 from pytensor.configdefaults import config, gcc_version_str
 from pytensor.configparser import BoolParam, StrParam
 from pytensor.graph.op import Op
-from pytensor.link.c.exceptions import CompileError, MissingGXX
 from pytensor.utils import (
     LOCAL_BITWIDTH,
     flatten,
@@ -266,6 +259,8 @@ class DynamicModule:
 
 def _get_ext_suffix():
     """Get the suffix for compiled extensions"""
+    from setuptools._distutils.sysconfig import get_config_var
+
     dist_suffix = get_config_var("EXT_SUFFIX")
     if dist_suffix is None:
         dist_suffix = get_config_var("SO")
@@ -1697,6 +1692,8 @@ def get_gcc_shared_library_arg():
 
 
 def std_include_dirs():
+    from setuptools._distutils.sysconfig import get_python_inc
+
     numpy_inc_dirs = [np.get_include()]
     py_inc = get_python_inc()
     py_plat_spec_inc = get_python_inc(plat_specific=True)
@@ -1709,6 +1706,12 @@ def std_include_dirs():
 
 @is_StdLibDirsAndLibsType
 def std_lib_dirs_and_libs() -> tuple[list[str], ...] | None:
+    from setuptools._distutils.sysconfig import (
+        get_config_var,
+        get_python_inc,
+        get_python_lib,
+    )
+
     # We cache the results as on Windows, this trigger file access and
     # this method is called many times.
     if std_lib_dirs_and_libs.data is not None:
@@ -2388,23 +2391,6 @@ class GCC_compiler(Compiler):
                 # xcode's version.
                 cxxflags.append("-ld64")
 
-        if sys.platform == "win32":
-            # Workaround for https://github.com/Theano/Theano/issues/4926.
-            # https://github.com/python/cpython/pull/11283/ removed the "hypot"
-            # redefinition for recent CPython versions (>=2.7.16 and >=3.7.3).
-            # The following nullifies that redefinition, if it is found.
-            python_version = sys.version_info[:3]
-            if (3,) <= python_version < (3, 7, 3):
-                config_h_filename = get_config_h_filename()
-                try:
-                    with open(config_h_filename) as config_h:
-                        if any(
-                            line.startswith("#define hypot _hypot") for line in config_h
-                        ):
-                            cxxflags.append("-D_hypot=hypot")
-                except OSError:
-                    pass
-
         return cxxflags
 
     @classmethod
@@ -2555,8 +2541,9 @@ class GCC_compiler(Compiler):
 
         """
         # TODO: Do not do the dlimport in this function
-
         if not config.cxx:
+            from pytensor.link.c.exceptions import MissingGXX
+
             raise MissingGXX("g++ not available! We can't compile c code.")
 
         if include_dirs is None:
@@ -2586,6 +2573,8 @@ class GCC_compiler(Compiler):
                 cppfile.write("\n")
 
         if platform.python_implementation() == "PyPy":
+            from setuptools._distutils.sysconfig import get_config_var
+
             suffix = "." + get_lib_extension()
 
             dist_suffix = get_config_var("SO")
@@ -2642,6 +2631,8 @@ class GCC_compiler(Compiler):
         status = p_out[2]
 
         if status:
+            from pytensor.link.c.exceptions import CompileError
+
             tf = tempfile.NamedTemporaryFile(
                 mode="w", prefix="pytensor_compilation_error_", delete=False
             )

pytensor/link/vm.py

@@ -19,7 +19,6 @@ from typing import TYPE_CHECKING, Any
 from pytensor.configdefaults import config
 from pytensor.graph.basic import Apply, Constant, Variable
 from pytensor.link.basic import Container, LocalLinker
-from pytensor.link.c.exceptions import MissingGXX
 from pytensor.link.utils import (
     gc_helper,
     get_destroy_dependencies,
@@ -1006,6 +1005,8 @@ class VMLinker(LocalLinker):
         compute_map,
         updated_vars,
     ):
+        from pytensor.link.c.exceptions import MissingGXX
+
         pre_call_clear = [storage_map[v] for v in self.no_recycling]
 
         try:

pytensor/scan/op.py

@@ -74,7 +74,6 @@ from pytensor.graph.op import HasInnerGraph, Op
 from pytensor.graph.replace import clone_replace
 from pytensor.graph.utils import InconsistencyError, MissingInputError
 from pytensor.link.c.basic import CLinker
-from pytensor.link.c.exceptions import MissingGXX
 from pytensor.printing import op_debug_information
 from pytensor.scan.utils import ScanProfileStats, Validator, forced_replace, safe_new
 from pytensor.tensor.basic import as_tensor_variable
@@ -1499,6 +1498,7 @@ class Scan(Op, ScanMethodsMixin, HasInnerGraph):
         then it must not do so for variables in the no_recycling list.
 
         """
+        from pytensor.link.c.exceptions import MissingGXX
 
         # Before building the thunk, validate that the inner graph is
         # coherent