(ref) correct differences between pkg-config and pkgconfig

setup.py

@@ -281,8 +281,11 @@ def has_c_libraries(self):
     if os.name == 'nt' or sys.platform == 'win32':
         # Apparently, the linker on Windows interprets -lxxx as xxx.lib, not libxxx.lib
         for i, v in enumerate(extension.__dict__.get('extra_link_args')):
-            if v.endswith('.lib'):
-                extension.__dict__['extra_link_args'][i] = f'lib{v}'
+            extension.__dict__['extra_link_args'][i] = v.replace('-L', '/LIBPATH:')
+
+            if v.startswith('-l'):
+                v = v.replace('-l', 'lib')
+                extension.__dict__['extra_link_args'][i] = f'{v}.lib'
 
     setup_kwargs = dict(
         setup_requires=['cffi>=1.3.0', 'requests'],

setup_support.py

@@ -62,10 +62,9 @@ def _find_lib():
     from cffi import FFI
 
     try:
-        # raises CalledProcessError if pkg-config is not installed or the lib does not exists
-        subprocess.check_output(['pkg-config', '--exists', 'libsecp256k1'])  # noqa S603
+        subprocess.check_output(['pkg-config', '--exists', 'libsecp256k1'], env=env)  # noqa S603
 
-        includes = subprocess.check_output(['pkg-config', '--cflags-only-I', 'libsecp256k1'])  # noqa S603
+        includes = subprocess.check_output(['pkg-config', '--cflags-only-I', 'libsecp256k1'], env=env)  # noqa S603
         includes = includes.strip().decode('utf-8')
 
         return os.path.exists(os.path.join(includes[2:], 'secp256k1_ecdh.h'))