macOS 26 (Darwin 25.5.0) introduced stricter Clang module map rules in
DarwinFoundation1.modulemap: the '_c_standard_library_obsolete' module
now requires the 'found_incompatible_headers__check_search_paths' feature,
which CLING's runtime interpreter does not set. When fftw3.h (from
/opt/homebrew/include) was parsed by CLING via the inlined PStartupHandler
dictionary payload, it triggered this module map error, causing all
PStartupHandler signal/slot connections to fail.
Two fixes:
- PMusr.h: guard '#include "fftw3.h"' with '#ifndef __CLING__'. No fftw
types appear in PMusr.h class definitions, so CLING does not need it
for reflection. This is the primary runtime fix.
- CMakeLists.txt (src/classes and all src/external libs): replace
'-I${FFTW3_INCLUDE}', '-I${Boost_INCLUDE_DIRS}', '-I${GSL_INCLUDE_DIRS}',
and '-I${ROOT_INCLUDE_DIRS}' with '-isystem' in all root_generate_dictionary
OPTIONS blocks, and change 'include_directories(${FFTW3_INCLUDE})' to
'include_directories(SYSTEM ...)'. Internal project paths (MUSRFIT_INC,
BMW_TOOLS_INC, NONLOCAL_INC, CMAKE_CURRENT_SOURCE_DIR, etc.) keep '-I'.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
suter_a