Why do I get Fortran 'End of record' error on PC with Fedora, but not on Macbook?

I have a program which works well when using Macbook, but as soon as I try it on PC with Fedora 28, I get this error:

At line 107 of file transport.f08
Fortran runtime error: End of record
Error termination. Backtrace:
#0  0x7f2e56fe039a
#1  0x7f2e56fe0f09
#2  0x7f2e56fe1711
#3  0x7f2e571e6818
#4  0x7f2e571f2022
#5  0x7f2e571e97fa
#6  0x7f2e571e9c14
#7  0x403e5a
#8  0x405d0c
#9  0x405e65
#10  0x7f2e5643b1ba
#11  0x400bc9
#12  0xffffffffffffffff

Here is the block of code with problematic line 107:

subroutine outputs(i_out)
    integer, intent(in) :: i_out
    integer :: iunit, ierr
    integer :: i

     character(len=8) :: chout
     write(chout,fmt='(I0.4)') i_out    ! LINE 107

     open(newunit=iunit,file="./outputs/Houtput"//trim(chout)//".dat",&
     action="write", iostat=ierr)

    if( ierr /= 0) then
            print *, " > There was an error while opening output file ", i_out
            print *, " > Exiting..."
            stop
    endif

    do i=1,Nr
            write(iunit,fmt='(20E14.6)') r_cell(i), velocity(i), pressure(i), density(i)
    enddo

    close(iunit)

end subroutine outputs

Solution

As francescalus pointed out in the comments, I had to drop i_out length to 8 or less digits. It solved the error.

I still don't know why it worked on Mac before, but having the error solved is enough for me :) Thanks.