sage: from sage.libs.fplll.fplll import FP_LLL
sage: FE = random_matrix(ZZ,10,10)
sage: FE # result random
[  2  -1  -1  -1  -3   1  -1 -32  -1  -1]
[  1   2  -1  -1   1   1  -1  -1   8   1]
[  1  -2  -2  -2  -6  -6   2  -1   1  -1]
[  3   3  -1   1   1   6   1   1  -1  -1]
[ -1  -1   1  -1  -2   3   1  -2   1  25]
[ -1   1   1 -10  -1  -1   1   1  -1   1]
[  1   1  25  -1   1  -4   4   5  -2   3]
[  3  -2   2  -6  -4   1  -1  -3  -1   1]
[  1  -4   2   3   1   1   1   2   3  -1]
[  6  -8   1  -1 -16   2 -25  -1  -2   2]
sage: F = FP_LLL(FE)
sage: F.fast_early_red()
Traceback (most recent call last):
...
RuntimeError: BUG: fast early reduction segfaults

0x00002b137bc2695d in __gmpz_get_d_2exp () from /usr/local/sage-2.8.1/local/lib/libgmp.so.3
(gdb) bt
#0  0x00002b137bc2695d in __gmpz_get_d_2exp () from /usr/local/sage-2.8.1/local/lib/libgmp.so.3
#1  0x00002b139820d63c in fast_early_red<__mpz_struct [1], double>::BabaiCall (this=0x1f310f0, alpha=<value optimized out>, zeros=-1, kappamax=2, var_k=<value optimized out>, ztmp=@0x7fff3036c7d0,
    newvec=@0x7fff3036c7ec, newvecmax=@0x7fff3036c7e8, n=10) at /usr/local/sage-2.8.1/local//include/fplll/nr.cpp:237
#2  0x00002b139821c65d in fast<__mpz_struct [1], double>::LLL (this=0x1f310f0) at /usr/local/sage-2.8.1/local//include/fplll/fast.cpp:591
#3  0x00002b139820b4ec in __pyx_f_py_5fplll_6FP_LLL_fast_early_red (__pyx_v_self=0x2b80d90, __pyx_args=<value optimized out>, __pyx_kwds=<value optimized out>) at sage/libs/fplll/fplll.cpp:1642