Changes

Rémy Mozul · a68f46af
--- a/faq.markdown
+++ b/faq.markdown
 # Frequently Asked Question #
 ## <a name=general_questions> General questions </a> ##
 ###### What is the license of this software ? ######
 This software is distributed under the [Free Software CECILL License]()
 ###### On which OS does it work ? ######
 Currently it works on UNIX OS (Linux, Solaris, MacOSX, etc). 
 Concerning Windows, a pre-compiled version is available for a specific version of Anaconda Python Distribution.
 Check the [prerequisites](https://git-xen.lmgc.univ-montp2.fr/lmgc90/lmgc90_user/wikis/prerequisites) section
 of the wiki.
 ###### What is needed to install ? ######
 Check the [prerequisites](https://git-xen.lmgc.univ-montp2.fr/lmgc90/lmgc90_user/wikis/prerequisites) section
 of the wiki.
 ###### I get the message "ImportError: No module named pylmgc90" when running an example, what is wrong ? ######
 Python did not find the module with lmgc90. If the path to your build directory is *my_build_path*,
 then make sure your ```PYTHONPATH``` environment variable is correctly set with:
 ```shell
 export PYTHONPATH=my_build_path
 ```
 or that you add the path inside your command script with the two lines:
 ```python
 import sys
 sys.path.append("my_build_path")
 ```
 ###### How to use multi-threaded version ? ####
 First the code must be re-compiled (unavailable on Windows).  
 Go to your build directory (if you followed the instruction of the wiki it should be *lmgc90_user/build*), then type the
 following command in your terminal:
 ```shell
 cmake . -DWITH_OPENMP=True
 ```
 Finally before running a computation, you must set two environment variables which are:
 ```shell
 export OMP_SCHEDULE=STATIC
 export OMP_NUM_THREADS=n
 export OPENBLAS_NUM_THREADS=1
 ```
 where **n** is the number of threads you want to use (usually no more than the number of core available).  
 Additional informations in: examples/Ateliers/Performance/directions/index.html
 ## <a name=compile_error> Known compilation errors </a> ##
 ##### An error arise at the very beginning when running `cmake` command ####
 * if the error message is something like:
 ```Text
  CMake generation for this library is not allowed within the source
  directory!
  Remove the CMakeCache.txt file and try again from another folder, e.g.:
     rm -r CMakeCache.txt CMakeFiles
     cd <somewhere (preferably a local place on your computer and not a network folder)>
     cmake <source directory of LMGC90>
  If you really need an in source build, then run : cmake
  -DIN_SOURCE_BUILD=ON
 Call Stack (most recent call first):
  CMakeLists.txt:21 (include)
 -- Configuring incomplete, errors occurred!
 ```
 Then it means you issued the `cmake` command within the base of your source
 directory. In this case, following the recommendation of the error message
 you have to remove, in the source directory the `CMakeCache.txt` file and
 the `CMakeFiles` directory. Then you can go back to step where you change of
 directory (`cd build`) before continuing the installation process.
-##### An error arise when building the `matlib` on Mac OS Yosemite ####
+##### An error arise when building on Mac OS ####
-* if the error is something like:
+On MacOS, at the time of writing (May 27th 2025) there may be an error during the `make` step:
+```
-```shell
+                 from /Users/mozul/WORK/LMGC90/sources/lmgc90_dev/src/contribs/clipper2-1.4.0/CPP/Clipper2Lib/src/clipper.engine.cpp:10:
-/usr/include/dispatch/object.h:143:15: error: expected ')' before '^' token
+/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/mach/arm/_structs.h:627:35: error: expected primary-expression before 'unsigned'
-/usr/include/dispatch/object.h:362:3: error: 'dispatch_block_t' has not been declared
+  627 | } __attribute__((aligned(_Alignof(unsigned int))));
-   dispatch_block_t notification_block);
+      |                                   ^~~~~~~~
-   ^
+```
-make[5]: *** [CMakeFiles/matlib.dir/src/math/eigmat.cpp.o] Error 1
-make[4]: *** [CMakeFiles/matlib.dir/all] Error 2
+In this case, following these instructions https://fluka-forum.web.cern.ch/t/geoviewer-compilation-error-on-macbook-pro-m4-macos-15-4/7246, you must:
-make[3]: *** [all] Error 2
+* Check that you are using the Command Line Tools (CLT) 16.3
-make[2]: *** [src/contribs/matlib-prefix/src/matlib-stamp/matlib-build] Error 2
+  * `pkgutil --pkg-info=com.apple.pkg.CLTools_Executables`
-make[1]: *** [src/contribs/CMakeFiles/matlib.dir/all] Error 2
+* Uninstall Xcode if installed
-make: *** [all] Error 2
+* Remove the command line tools:
-```
+  * `sudo rm -rf /Library/Developer/CommandLineTools`
+* Download and install CLT 16.2 from  [Apple Developer website](https://developer.apple.com/download/all/)
-Then you can:
+* Clean your build directory and start over...
-* shut down the MatLib if you do not need it:
-```shell
+| [back](./Documentation) | [home](./Home) |
-cmake . -DMATLIB_VERSION=none
-make
-```
-* or modifiy the file *src/contribs/MatLib4-LMGC-2015-1/src/math/lapack.h* so that it looks like this:
-```
- #ifndef ZORGLIB_MATH_LAPACK_H
- #define ZORGLIB_MATH_LAPACK_H
- #ifndef __has_extension
- #define __has_extension(x) 0
- #endif
- #define vImage_Utilities_h
- #define vImage_CVUtilities_h
- // config
- #include <matlib_macros.h>
-```
-Then run `make` again.
-****
-| [back](./Documentation) | [home](./Home) |
 |:---------------------|---------------:|
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