[Help-glpk] Assertion failed

[nghafour]

Hi,

I have a problem with running glpk-4.10:

I run the following MIP instance using command (glpsol --cpxlp ~/tmp_prob.lp):

Minimize
 obj: x_1

Subject To
 r_1: - 1003 x_1 + x_2 >= 0
 r_2: - 1999 x_2 + x_3 >= 0
 r_3: - 4000 x_3 + x_4 >= 0
 r_4: + 8000 x_4 + x_5 <= 0
 r_5: + 2 x_5 + x_6 >= 0
 r_6: - x_1 <= -1002
 r_7: - x_2 <= -1005006
 r_8: - x_3 <= 138476654
 r_9: - x_4 <= -144165184
 r_10: - x_6 <= -1

Bounds
 x_1 free
 x_2 free
 x_3 free
 x_4 free
 x_5 free
 x_6 free

Generals
 x_1
 x_2
 x_3
 x_4
 x_5
 x_6

End

and I get the following output (error):

lpx_read_cpxlp: 10 rows, 6 columns, 15 non-zeros
lpx_read_cpxlp: 6 integer columns, none of which are binary
lpx_read_cpxlp: 32 lines were read
lpx_simplex: original LP has 10 rows, 6 columns, 15 non-zeros
lpx_simplex: presolved LP has 5 rows, 6 columns, 10 non-zeros
lpx_adv_basis: size of triangular part = 5
      0:   objval =   1.002000000e+03   infeas =   1.000000000e-00 (0)
Assertion failed: spx->p != 0; file glpspx2.c; line 668

It seems like an error in glpk or is there anything I should do to be able to
solve this problem?

Thanks,

Niloufar