Another issue with failed to compile with mpif90 $(pkg-config --cflags --libs scifor) test.f95

[WangYun1995]

Firstly, I installed mpi. And I follow the make post-install instructions completely.
Secondly, I write one tested code for testing the interpolation functionality of scifor.

Module ParameterPack
    Implicit None
	Real(8), Parameter :: Pi=3.1415926535897932384626d0
    Integer, Parameter :: Nt = 1025
    Real(8), Save :: Array(2, 1:Nt)
End Module ParameterPack

! ------------------------------------------------------------------------------

! -----------------------------------------------------------------------------!
Module FunPack
   Use ParameterPack
   Use Scifor
   Implicit None
! ------------------------------------------------------------------!
!     (1) Function Fun(x)                                           !
! ------------------------------------------------------------------!
Contains
! -----------------------------------------------------------------------------!
  Function Fun(x)
     Real(8) :: Fun
     Real(8), Intent(in) :: x
     Integer, Save :: Iswitch = 0
     Real(8) :: yout
	 Real(8), Dimension(Nt) :: xin, yin
! ----------------------------------------------------------------------------!
     xin = Array(1,:)
	 yin = Array(2,:)
     Call cubic_spline(xin, yin, x, yout)
     Fun = yout
     Return
  End Function Fun
! -----------------------------------------------------------------------------
End Module FunPack

! -----------------------------------------------------------------------------!
Program InterPolate
   Use ParameterPack
   Use Scifor
   Use FunPack
   Implicit None
   Integer :: loop, i
   Real(8) :: dx, x, y
   Real(8), Dimension(1:Nt) :: line_gas
   Real :: ttime
! -----------------------------------------------------------------------------
   
   Open(11, file="line_gas.dat")
   Do i = 1, Nt
     Read(11,*) line_gas(i)
   End Do
! -----------------------------------------------------------------------------
   dx = 75.0d0/(Nt-1)
   Do loop = 1, Nt
     x = dx*(loop-1)
     Array(1, loop) = x
     Array(2, loop) = line_gas(loop)
   End Do
! -----------------------------------------------------------------------------
   Open(10, file="dt_sci_gas.dat")
   Do loop = 0, 75000
      x = 0.001d0*loop
      y = Fun(x)
      Write(10, *) x, y
   EndDo
   Close(10)
! -----------------------------------------------------------------------------
   Call CPU_time(ttime)
   Write(*,*) "-----------------------------------------------------------"
   Write(*,*) "ttime=:", ttime
! ------------------------------------------------------------------
End Program InterPolate

After I input
$ mpif90 $(pkg-config --cflags --libs scifor) test_cubic_spline.f95
It returned an error to me as follows.

/tmp/ccBaLEme.o: In function `__funpack_MOD_fun':
test_cubic_spline.f95:(.text+0xd8): undefined reference to `__sf_interpolate_MOD_d_cub_interp_s'
collect2: error: ld returned 1 exit status

However, it works when I compile this code by gfortran test_cubic_spline.f95 -I/home/wangy/opt/scifor/gnu/4.6.31/include -L/home/wangy/opt/scifor/gnu/4.6.31/lib -lscifor.

[aamaricci]

If the output of $(pkg-config --cflags --libs scifor) command is wrong then the linking is ineffective and returns undefined reference, i.e. the procedure can not be find in any provided library or object file.
The explicit string you supply is correct and make the compilation works (you can safely replace fortran with mpif90).
Follow the instructions on the other issue to fix pkg-config. Then everything should work fine.

Your code compiled as a piece of cake on my system.