确定安装了正确版本的cuba库，并且已将库路径添加到LD_LIBRARY_PATH环境变量中。如果问题仍然存在，请检查是否正确包含了cuba库的头文件（例如，使用-lcuba选项）。以下是一个cuba库的示例代码：

program cuba_test use cuba real8, parameter :: epsrel = 1.0e-3 integer, parameter :: ncomp = 1, nregions = 1 integer :: neval, fail real8 :: integral(ncomp), error(ncomp) real8 :: bounds(2, 6) = reshape([0.0d0, pi, 0.0d0, pi, 0.0d0, 2.0d0pi], [2, 6]) external :: integrand call vegas(integrand, 6, bounds, ncomp, epsrel, nregions, neval, integral, error, fail) print , 'Result:', integral(1), '+/-', error(1) contains function integrand(ndim, x, ncomp, integrand_res, userdata) real8 :: x(6), integrand_res(ncomp) integrand_res(1) = sin(x(1)) * sin(x(2)) * sin(x(3)) * cos(x(4)) * exp(x(5)) / (1.0d0 + x(6)**2) return end function integrand end program cuba_test