I'm trying to make use of the ecl::geometry package, and in doing so must use ecl::array as a container for the inputs. I'm running Ubuntu 18 and Melodic. The relevant lines of code are:

std::vector<ecl::SmoothLinearSpline> splines;
    const unsigned int numPtsConst = numPts;
    ecl::Array<double> ecl_pos(numPts);
    ecl::Array<double> ecl_time(numPts);
    for(int i = 1;i<numJts;i++){
        for(int j = 1;j<numPts;j++){
            ecl_pos[j] = t1[i].positions_[j];
            ecl_time[j] = t1[i].time_from_start_[j];
        }
        double maxAcc = 3*t1[i].max_velocity_;

    }

and the error I encounter is

CMakeFiles/runpath_server.dir/src/runpath_server.cpp.o: In function `ecl::StandardException::~StandardException()':
runpath_server.cpp:(.text._ZN3ecl17StandardExceptionD2Ev[_ZN3ecl17StandardExceptionD5Ev]+0xf): undefined reference to `vtable for ecl::StandardException'
CMakeFiles/runpath_server.dir/src/runpath_server.cpp.o: In function `ecl::Array<double, 0ul>::operator[](unsigned long)':
runpath_server.cpp:(.text._ZN3ecl5ArrayIdLm0EEixEm[_ZN3ecl5ArrayIdLm0EEixEm]+0x3f): undefined reference to `ecl::StandardException::StandardException(char const*, ecl::ErrorFlag)'
runpath_server.cpp:(.text._ZN3ecl5ArrayIdLm0EEixEm[_ZN3ecl5ArrayIdLm0EEixEm]+0x4d): undefined reference to `typeinfo for ecl::StandardException'
collect2: error: ld returned 1 exit status

Any assistance in identifying the source of this compilation error would be hugely appreciated.