GR-43512: scipy 1.8.1 - cyhtonize in process

Author: cosminbasca

graalpython/lib-graalpython/patches/scipy/sdist/scipy-1.8.1.patch

@@ -1,5 +1,5 @@
 diff --git a/scipy/__init__.py b/scipy/__init__.py
-index f4af2ad8e..de3025b3c 100644
+index f4af2ad8..de3025b3 100644
 --- a/scipy/__init__.py
 +++ b/scipy/__init__.py
 @@ -157,4 +157,4 @@ else:
@@ -8,3 +8,54 @@ index f4af2ad8e..de3025b3c 100644
      # This makes "from scipy import fft" return scipy.fft, not np.fft
 -    del fft
 +    # del fft
+diff --git a/tools/cythonize.py b/tools/cythonize.py
+index 2e0179be..e6d71484 100755
+--- a/tools/cythonize.py
++++ b/tools/cythonize.py
+@@ -95,24 +95,23 @@ def process_pyx(fromfile, tofile, cwd):
+     if tofile.endswith('.cxx'):
+         flags += ['--cplus']
+ 
+-    try:
++    try:    
++        from Cython.Compiler.Main import setuptools_main
++        prev_argv = sys.argv[1:]
+         try:
+-            r = subprocess.call(['cython'] + flags + ["-o", tofile, fromfile], cwd=cwd)
+-            if r != 0:
+-                raise Exception('Cython failed')
+-        except OSError as e:
+-            # There are ways of installing Cython that don't result in a cython
+-            # executable on the path, see gh-2397.
+-            r = subprocess.call([sys.executable, '-c',
+-                                 'import sys; from Cython.Compiler.Main import '
+-                                 'setuptools_main as main; sys.exit(main())'] + flags +
+-                                 ["-o", tofile, fromfile],
+-                                cwd=cwd)
+-            if r != 0:
+-                raise Exception("Cython either isn't installed or it failed.") from e
++            oldcwd = os.getcwd()
++            os.chdir(cwd)
++            sys.argv[1:] = flags + ["-o", tofile, fromfile]
++            retcode = setuptools_main()
++            if retcode:
++                sys.exit(retcode)
++        finally:
++            sys.argv[1:] = prev_argv
++            os.chdir(oldcwd)
+     except OSError as e:
+         raise OSError('Cython needs to be installed') from e
+ 
++
+ def process_tempita_pyx(fromfile, tofile, cwd):
+     try:
+         try:
+@@ -253,7 +252,7 @@ def find_process_files(root_dir):
+     lock = Lock()
+ 
+     try:
+-        num_proc = int(os.environ.get('SCIPY_NUM_CYTHONIZE_JOBS', cpu_count()))
++        num_proc = int(os.environ.get('SCIPY_NUM_CYTHONIZE_JOBS', 1))
+         pool = Pool(processes=num_proc)
+     except ImportError as e:
+         # Allow building (single-threaded) on GNU/Hurd, which does not