Compilation error due to MPI and missing FORTRAN

When trying to compile Online on machines where it says:

-- +======================================================================+
-- |   PCIE40 DAQ found.  EventBuilding libraries shall be built.         |
-- +======================================================================+

the compilation fails with:

-- Could NOT find MPI_C (missing: MPI_C_LIB_NAMES MPI_C_HEADER_DIR MPI_C_WORKS) 
-- Could NOT find MPI_CXX (missing: MPI_CXX_LIB_NAMES MPI_CXX_HEADER_DIR MPI_CXX_WORKS) 
CMake Error at /cvmfs/lhcb.cern.ch/lib/var/lib/LbEnv/2062/stable/linux-64/share/cmake-3.19/Modules/FindPackageHandleStandardArgs.cmake:218 (message):
  Could NOT find MPI (missing: MPI_C_FOUND MPI_CXX_FOUND)

      Reason given by package: MPI component 'Fortran' was requested, but language Fortran is not enabled.  

Call Stack (most recent call first):
  /cvmfs/lhcb.cern.ch/lib/var/lib/LbEnv/2062/stable/linux-64/share/cmake-3.19/Modules/FindPackageHandleStandardArgs.cmake:582 (_FPHSA_FAILURE_MESSAGE)
  /cvmfs/lhcb.cern.ch/lib/var/lib/LbEnv/2062/stable/linux-64/share/cmake-3.19/Modules/FindMPI.cmake:1722 (find_package_handle_standard_args)
  Online/EventBuilding/CMakeLists.txt:38 (find_package)


-- Configuring incomplete, errors occurred!

Is there something wrong with the CMake file and is there a fix which does not involve removing the EventBuilding package? Compilation works on machines where PCIE40 DAQ is not found. That is also why it does not fail in the nightlies.