The below fixes the build of py-ptyprocess under Python 3.12 by adding 
MODPY_PYBUILD=flit_core.

ok?

Index: Makefile
===================================================================
RCS file: /cvs/ports/devel/py-ptyprocess/Makefile,v
diff -u -p -u -r1.12 Makefile
--- Makefile	13 Nov 2022 15:28:19 -0000	1.12
+++ Makefile	17 Jan 2024 18:02:13 -0000
@@ -1,7 +1,7 @@
 COMMENT =		run a subprocess in a pseudo terminal
 
 MODPY_EGG_VERSION =	0.7.0
-REVISION =		2
+REVISION =		3
 DISTNAME =		ptyprocess-${MODPY_EGG_VERSION}
 PKGNAME =		py-${DISTNAME}
 
@@ -13,7 +13,9 @@ HOMEPAGE =		https://github.com/pexpect/p
 PERMIT_PACKAGE =	Yes
 
 MODULES =		lang/python
+
 MODPY_PI =		Yes
+MODPY_PYBUILD =		flit_core
 MODPY_PYTEST =		Yes
 
 FLAVORS =		python3
Index: pkg/PLIST
===================================================================
RCS file: /cvs/ports/devel/py-ptyprocess/pkg/PLIST,v
diff -u -p -u -r1.6 PLIST
--- pkg/PLIST	11 Mar 2022 18:52:53 -0000	1.6
+++ pkg/PLIST	17 Jan 2024 18:02:13 -0000
@@ -1,11 +1,19 @@
 @pkgpath devel/py-ptyprocess
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/
-lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}-py${MODPY_VERSION}.egg-info
+lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}.dist-info/
+lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}.dist-info/LICENSE
+lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}.dist-info/METADATA
+lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}.dist-info/RECORD
+lib/python${MODPY_VERSION}/site-packages/ptyprocess-${MODPY_EGG_VERSION}.dist-info/WHEEL
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/__init__.py
 ${MODPY_COMMENT}lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}/
+lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}__init__.${MODPY_PYC_MAGIC_TAG}${MODPY_PYOEXTENSION}
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}__init__.${MODPY_PYC_MAGIC_TAG}pyc
+lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}_fork_pty.${MODPY_PYC_MAGIC_TAG}${MODPY_PYOEXTENSION}
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}_fork_pty.${MODPY_PYC_MAGIC_TAG}pyc
+lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}ptyprocess.${MODPY_PYC_MAGIC_TAG}${MODPY_PYOEXTENSION}
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}ptyprocess.${MODPY_PYC_MAGIC_TAG}pyc
+lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}util.${MODPY_PYC_MAGIC_TAG}${MODPY_PYOEXTENSION}
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/${MODPY_PYCACHE}util.${MODPY_PYC_MAGIC_TAG}pyc
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/_fork_pty.py
 lib/python${MODPY_VERSION}/site-packages/ptyprocess/ptyprocess.py