O2 build fails in FairRot@v18.4.1 on ubuntu 20.04

Dear all,
I can’t build O2 on ubuntu 20.04, it fails in FairRoot complaining in the following way:

CMake Error in fairtools/MCConfigurator/CMakeLists.txt:
Imported target “yaml-cpp” includes non-existent path


in its INTERFACE_INCLUDE_DIRECTORIES. Possible reasons include:

  • The path was deleted, renamed, or moved to another location.
  • An install or uninstall procedure did not complete successfully.
  • The installation package was faulty and references files it does not

It seems to me a problem related to boost (a package that is build by aluBuild in my case).

Does anybody have a useful suggestion to overcome this problem?

Thanks in advance, kind regards,

Hi Chiara,

I had a similar issue and used the following workaround: in alidist/yaml-cpp.sh I simply commented out the line starting with “prefer_system:” and the following two lines as well. That way aliBuild always builds yaml-cpp, although you have the dependency already installed on your system. And that way cmake finds yaml-cpp correctly during the compilation of FairRoot.

Of course this is not a real fix, since it builds yaml-cpp although that should not be necessary. But it works well for me…


Dear Ole,
thank you very much! It worked!!! :slight_smile: