anchor.diff:    call f_close(93)
   
   #ifdef BOINC
  -  call copyToStdErr(91,"fort.91")
  +  call copyToStdErr(91,"fort.91",10)
     call boinc_finish(errout) ! This call does not return
   #else
  +  call copyToStdErr(91,"fort.91",50)
     if(errout /= 0) then
  -    write(error_unit,"(a,i0)") "ABEND> ERROR Stopping with error ",errout
  +    ! Don't write to stderr, it breaks the error tests.
  +    write(output_unit,"(a,i0)") "ABEND> ERROR Stopping with error ",errout
       stop 1
     else
       stop
  
positive.code: ! ================================================================================================ !
  subroutine abend(cstring)
  
    use, intrinsic :: iso_fortran_env, only : error_unit
  
    use crcoall
    use parpro
  
negative.code: !  It is mainly used just before exiting SixTrack in case there was an error.
  !  This is useful since STDERR is often returned from batch systems and BOINC.
  ! =================================================================================================
  subroutine copyToStdErr(fUnit,fName,maxLines)
  
    use parpro
    use mod_units
  