The generator matrix

 1  0  0  1  1  1  X  1  1  1  1  0  1  X  1
 0  1  0  1  0 X+1  1  0  X  X  1  1 X+1  1  0
 0  0  1  1  1  0  1  X  1  1 X+1  1  X  0  0
 0  0  0  X  0  X  0  X  X  0  X  X  0  0  0
 0  0  0  0  X  0  0  0  X  0  X  X  X  X  0

generates a code of length 15 over Z2[X]/(X^2) who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+78x^12+60x^14+55x^16+32x^18+26x^20+4x^22

The gray image is a linear code over GF(2) with n=30, k=8 and d=12.
As d=12 is an upper bound for linear (30,8,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 8.
This code was found by Heurico 1.16 in 0.00272 seconds.