python: set CXX to prevent sccache detection in meson via

graphics/py-matplotlib with MODPY_PYBUILD=mesonpy via /usr/local/lib/python3.14/site-packages/mesonbuild/envconfig.py: return ExternalProgram('sccache', silent=True) detects /usr/local/bin/sccache and uses that over default "c++", leading to build failure with PORTS_PRIVSEP=yes: sccache: error: failed to create directory `/py-matplotlib-3.10.8_writes_to_HOME/.cache/sccache/preprocessor`: Permission denied (os error 13) Environmental CXX takes priority, but is not set compared to CC, which is how I tracked this down not knowing anything about how Python builds C++ code. Setting CXX where CC comes from fixes it and seems safe. tb@ mentioned COMPILER_LANGS, but I don't fully understand the implications of having CXX in the environment for Python ports doing COMPILER_LANGS=C (if they exist), so I just gated it. This fixes matplotlib for me when sccache is installed. Feedback? OK? Index: python.port.mk =================================================================== RCS file: /cvs/ports/lang/python/3/python.port.mk,v diff -u -p -r1.28 python.port.mk --- python.port.mk 19 Jun 2026 13:49:04 -0000 1.28 +++ python.port.mk 4 Sep 2026 16:56:30 -0000 @@ -224,6 +224,9 @@ MODPY_DISTUTILS_INSTALL ?= install --pre --root=${DESTDIR} MAKE_ENV += CC=${CC} +.if ${COMPILER_LANGS:Mc++} +MAKE_ENV += CXX=${CXX} +.endif CONFIGURE_ENV += PYTHON="${MODPY_BIN}" .if ${CONFIGURE_STYLE:Mgnu} CONFIGURE_ENV += ac_cv_prog_PYTHON="${MODPY_BIN}" \