Compilation error in src/gdl2gdl.cpp with clang 19

[thierry-FreeBSD]

Trying to compile gdl-v1.1 on FreeBSD-CURRENT (with clang-19) fails with these errors:

--- src/CMakeFiles/gdl.dir/gdl2gdl.cpp.o ---
/usr/ports/science/gnudatalanguage/work/gdl-v1.1/src/gdl2gdl.cpp:422:81: error: comparison between pointer and integer ('messageBoxHandle' (aka '__mq *') and 'int')
  422 |   if ((h = mq_open(name.c_str(), O_RDONLY | O_CREAT, QUEUE_PERMISSIONS, &attr)) == -1) {
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~
/usr/ports/science/gnudatalanguage/work/gdl-v1.1/src/gdl2gdl.cpp:433:79: error: comparison between pointer and integer ('messageBoxHandle' (aka '__mq *') and 'int')
  433 |   if ((gdl2gdlMessageBoxHandle = mq_open(g2gClientMailbox.c_str(), O_WRONLY)) == -1) {
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~
2 errors generated.
*** [src/CMakeFiles/gdl.dir/gdl2gdl.cpp.o] Error code 1

make[2]: stopped making "src/CMakeFiles/gdl.dir/build" in /usr/ports/science/gnudatalanguage/work/.build
make[2]: 1 error

make[2]: stopped making "src/CMakeFiles/gdl.dir/build" in /usr/ports/science/gnudatalanguage/work/.build
*** [src/CMakeFiles/gdl.dir/all] Error code 2

make[1]: stopped making "all" in /usr/ports/science/gnudatalanguage/work/.build
make[1]: 1 error

make[1]: stopped making "all" in /usr/ports/science/gnudatalanguage/work/.build
*** [all] Error code 2

make: stopped making "all" in /usr/ports/science/gnudatalanguage/work/.build
make: 1 error

make: stopped making "all" in /usr/ports/science/gnudatalanguage/work/.build

[GillesDuvert]

mq_open seems to return a different type on BSD than on other platforms. to be cured. Thanks.