[CMakeFiles/Makefile2:1680: VINS-Fusion/vins_estimator/CMakeFiles/vins_lib.dir/all] Error 2

This error message is indicating that there was an error in compiling the "vins_lib" directory of the "vins_estimator" project during the make process.

Without more context or information about the specific error, it is difficult to provide a more detailed solution. However, some common reasons for this type of error include missing dependencies or incorrect configuration settings in the CMakeLists.txt file.

To troubleshoot this issue, you can try the following steps:

1. Check the dependencies of the "vins_lib" directory and make sure they are correctly installed and configured.

2. Make sure that the CMakeLists.txt file for the "vins_estimator" project is correctly configured and all necessary components are included.

3. Check the build logs for any specific error messages that may indicate the cause of the problem.

4. Try cleaning the build directory and rebuilding the project to see if that resolves the issue.

If none of these steps work, you may need to seek further assistance from the project's community or support team.