partially backout an upstream commit which breaks packaging with python 2

(math/prover9 still uses python 2.7).

devel/py-modulegraph/Makefile

@@ -1,24 +1,27 @@
-COMMENT=		Python module dependency analysis tool
+COMMENT=	Python module dependency analysis tool
 
 MODPY_EGG_VERSION=	0.19.3
-DISTNAME=		modulegraph-${MODPY_EGG_VERSION}
-PKGNAME=		py-${DISTNAME}
+DISTNAME=	modulegraph-${MODPY_EGG_VERSION}
+PKGNAME=	py-${DISTNAME}
+REVISION=	0
 
-CATEGORIES=		devel
+CATEGORIES=	devel
 
 # MIT
-PERMIT_PACKAGE=		Yes
+PERMIT_PACKAGE=	Yes
 
-MODULES=		lang/python
+MODULES=	lang/python
 
-MODPY_PI =		Yes
-MODPY_SETUPTOOLS=	Yes
+MODPY_PI=	Yes
 
 # math/prover9/p9m4 still uses py2
-FLAVORS =		python3
+MODPY_SETUPTOOLS=	Yes
+FLAVORS =	python3
 FLAVOR ?=
 
-RUN_DEPENDS=		devel/py-altgraph${MODPY_FLAVOR}
+RUN_DEPENDS=	devel/py-altgraph${MODPY_FLAVOR}
+TEST_DEPENDS=	${RUN_DEPENDS} \
+		lang/python/${MODPY_VERSION},-idle
 
 post-install:
 	mv ${PREFIX}/bin/modulegraph{,${MODPY_BIN_SUFFIX}}

devel/py-modulegraph/patches/patch-modulegraph_util_py

@@ -0,0 +1,14 @@
+Revert part of 415bc766401122 which breaks packaging with py2
+
+Index: modulegraph/util.py
+--- modulegraph/util.py.orig
++++ modulegraph/util.py
+@@ -105,7 +105,7 @@ def imp_walk(name):
+     raise ImportError("No module named %s" % (name,))
+ 
+ 
+-cookie_re = re.compile(rb"coding[:=]\s*([-\w.]+)")
++cookie_re = re.compile(br"coding[:=]\s*([-\w.]+)")
+ if sys.version_info[0] == 2:
+     default_encoding = "ascii"
+ else: