src/sage_setup/command/sage_build_cython.py: Remove top-level imports…

… from sage.env, Cython

src/sage_setup/command/sage_build_cython.py

@@ -13,12 +13,8 @@
 from distutils.errors import (DistutilsModuleError,
                               DistutilsOptionError)
 
-from Cython.Build.Dependencies import default_create_extension
 from sage_setup.util import stable_uniq
 from sage_setup.find import find_extra_files
-from sage_setup.library_order import library_order
-
-from sage.env import (cython_aliases, sage_include_directories)
 
 # Do not put all, but only the most common libraries and their headers
 # (that are likely to change on an upgrade) here:
@@ -57,13 +53,6 @@
 if subprocess.call("""$CC --version | grep -i 'gcc.* 4[.]8' >/dev/null """, shell=True) == 0:
     extra_compile_args.append('-fno-tree-copyrename')
 
-# Search for dependencies in the source tree and add to the list of include directories
-include_dirs = sage_include_directories(use_sources=True)
-
-# Look for libraries only in what is configured already through distutils
-# and environment variables
-library_dirs = []
-
 class sage_build_cython(Command):
     name = 'build_cython'
     description = "compile Cython extensions into C/C++ extensions"
@@ -225,6 +214,13 @@ def run(self):
         Call ``cythonize()`` to replace the ``ext_modules`` with the
         extensions containing Cython-generated C code.
         """
+        from sage.env import (cython_aliases, sage_include_directories)
+        # Set variables used in self.create_extension
+        from ..library_order import library_order
+        self.library_order = library_order
+        # Search for dependencies in the source tree and add to the list of include directories
+        self.sage_include_dirs = sage_include_directories(use_sources=True)
+
         from Cython.Build import cythonize
         import Cython.Compiler.Options
 
@@ -295,7 +291,7 @@ def create_extension(self, template, kwds):
         # Libraries: sort them
         libs = kwds.get('libraries', [])
         kwds['libraries'] = sorted(set(libs),
-                key=lambda lib: library_order.get(lib, 0))
+                key=lambda lib: self.library_order.get(lib, 0))
 
         # Dependencies: add setup.py and lib_headers
         depends = kwds.get('depends', []) + [self.distribution.script_name]
@@ -336,11 +332,13 @@ def create_extension(self, template, kwds):
         kwds['extra_link_args'] = stable_uniq(ldflags)
 
         # Process library_dirs
-        lib_dirs = kwds.get('library_dirs', []) + library_dirs
+        lib_dirs = kwds.get('library_dirs', [])
         kwds['library_dirs'] = stable_uniq(lib_dirs)
 
         # Process include_dirs
-        inc_dirs = kwds.get('include_dirs', []) + include_dirs + [self.build_dir]
+        inc_dirs = kwds.get('include_dirs', []) + self.sage_include_dirs + [self.build_dir]
         kwds['include_dirs'] = stable_uniq(inc_dirs)
 
+        from Cython.Build.Dependencies import default_create_extension
+
         return default_create_extension(template, kwds)