Question about McCAD

[Frozaccio]

Dear McCad developers,

I have one question and one issue.
Question: Is McCAD library 1.1 similar to McCAD salome 0.5.1 in terms of performance and capabilities?
Issue: I tried to compile McCAD library 1.1 following the documentation. The compilation does not find the info.hpp file. I replaced the call to info.hpp with the manual version number in the code files. The compilation went well with this change but when I try to run McCAD, I get a segmentation fault with no backtrace. I compiled on ubuntu 22.04.

Thank you in advance for your help.
Best

[moatazharb]

Hello,
Thank you for your question and raising the issue. Please, find my replies below.

Question: While McCAD library 1.1 is based on the core decomposition algorithms of the salome version, it diverged a lot in terms of code structure and capabilities. McCAD v1.1 is expanded with more use cases for decomposition such as tori simplification, conical surface support, pipes simplification, etc. On the conversion side it got a totally new and robust algorithm which is totally different than its predecessor. The current develop branch contains some bug fixes and updates that are not yet pushed to the main branch. You are invited to use that branch.

Issue: This issue has been discovered for a while now and we are working on it! The source of the segmentation fault on Linux is still unknown. As of now, unfortunately, you can only use the Windows version! What lengthens the debugging process is that not much useful information is returned by the debugger! This then necessitates a brute force debugging process to try to locate the source of the error!

Thank you

[Frozaccio]

Thank you for your responses.

Here is the fix I found for the info.hpp file as well as resolving the segmentation fault:

1. Info.hpp: this is due to the fact I install McCAD in a different folder than the build folder. Hence I need to copy the info folder from the install_folder to the build_folder
   sudo cp -r ../install/src/info src/
2. Segmentation fault seems to be triggered by -DBUILD_SHARED=true
   Doing the following cmake call works ../../cmake-3.26.1/install/bin/cmake .. -DCMAKE_INSTALL_PREFIX=../install -DBUILD_RPATH=true -DBUILD_SHARED_EXE=true -DBOOST_CUSTOM_ROOT=/mnt/d/OneDrive/Library/boost_1_81_0 -DOCC_CUSTOM_ROOT=/usr/local/opencascade-7.7.0/install -DCMAKE_EXE_LINKER_FLAGS="-m64 -fPIC" -DCMAKE_CXX_FLAGS="-fPIC -std=c++17"

Best

[FThomas-Fr]

Hello, is there any news on a new version or a fix ?

[raska-s]

Hi, has there been any updates regarding this issue? If not, does the fix mentioned by @Frozaccio require using a static library for OCC?

[bauj]

Thank you for your responses.

Here is the fix I found for the info.hpp file as well as resolving the segmentation fault:

1. **Info.hpp**: this is due to the fact I install McCAD in a different folder than the build folder. Hence I need to copy the info folder from the install_folder to the build_folder
   sudo cp -r ../install/src/info src/

2. **Segmentation fault** seems to be triggered by -DBUILD_SHARED=true
   Doing the following cmake call works ../../cmake-3.26.1/install/bin/cmake .. -DCMAKE_INSTALL_PREFIX=../install -DBUILD_RPATH=true -DBUILD_SHARED_EXE=true -DBOOST_CUSTOM_ROOT=/mnt/d/OneDrive/Library/boost_1_81_0 -DOCC_CUSTOM_ROOT=/usr/local/opencascade-7.7.0/install -DCMAKE_EXE_LINKER_FLAGS="-m64 -fPIC" -DCMAKE_CXX_FLAGS="-fPIC -std=c++17"

Best

Hello, @Frozaccio I have the same issue with the Segmentation fault happening on an Ubuntu 22.04. I tried your fix (removing the -DBUILD_SHARED=true from the cmake command) but a lot of the cmake compilation process are based on this bool. Did you also tweak the CMake files to avoid using the BUILD_SHARED boolean ?

Thanks