devel/glibmm26: add new port with 2.68 API/ABI (stable branch) (+)

Time to strart transition from the outdated glibmm-2.4 API to the latest 2.68 API.
This port provide a latest release of glibmm-2.68 API, 2.74.0

Changelog since latest 2.4 API releases:

https://gitlab.gnome.org/GNOME/glibmm/-/blob/master/NEWS

devel/Makefile

@@ -827,6 +827,7 @@
     SUBDIR += glademm
     SUBDIR += glib20
     SUBDIR += glibmm
+    SUBDIR += glibmm26
     SUBDIR += gllvm
     SUBDIR += global
     SUBDIR += glog

devel/glibmm26/Makefile

+PORTNAME=	glibmm
+PORTVERSION=	2.74.0
+CATEGORIES=	devel
+MASTER_SITES=	GNOME
+PKGNAMESUFFIX=	26
+DIST_SUBDIR=	gnome
+
+MAINTAINER=	gnome@FreeBSD.org
+COMMENT=	C++ interfaces for glib2
+WWW=		https://www.gtkmm.org/
+
+LICENSE=	LGPL21
+
+USES=		compiler:c++11-lang gettext gnome meson pathfix perl5 \
+		pkgconfig python:3.7+,build shebangfix tar:xz
+USE_GNOME=	glib20 libsigc++30
+USE_LDCONFIG=	yes
+
+SHEBANG_GLOB=	*.py
+
+MESON_ARGS=	-Dbuild-documentation=false
+
+PORTSCOUT=	limit:^2\.72
+PLIST_SUB=	VERSION=2.68
+
+.include <bsd.port.mk>

devel/glibmm26/distinfo

+TIMESTAMP = 1667733887
+SHA256 (gnome/glibmm-2.74.0.tar.xz) = 2b472696cbac79db8e405724118ec945219c5b9b18af63dc8cfb7f1d89b0f1fa
+SIZE (gnome/glibmm-2.74.0.tar.xz) = 7938292

devel/glibmm26/pkg-descr

+C++ interfaces for glib20.