gahs@gahs-HP-Mini-210-1100:~/gpredict$ gdb install-1.3/bin/gpredict 
GNU gdb (Ubuntu/Linaro 7.2-1ubuntu11) 7.2
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Reading symbols from /home/gahs/gpredict/install-1.3/bin/gpredict...done.
(gdb) run
Starting program: /home/gahs/gpredict/install-1.3/bin/gpredict 
[Thread debugging using libthread_db enabled]
[New Thread 0xb5533b70 (LWP 14051)]
[New Thread 0xb4bffb70 (LWP 14052)]
[Thread 0xb5533b70 (LWP 14051) exited]
[New Thread 0xb5533b70 (LWP 14055)]
[Thread 0xb5533b70 (LWP 14055) exited]
^C
Program received signal SIGINT, Interrupt.
0x080555b6 in Magnitude (v=0xbfffe0c0) at sgpsdp/sgp_math.c:89
89	  v->w = sqrt(Sqr(v->x) + Sqr(v->y) + Sqr(v->z));
(gdb) bt
#0  0x080555b6 in Magnitude (v=0xbfffe0c0) at sgpsdp/sgp_math.c:89
#1  0x08055a7a in Calculate_User_PosVel (_time=nan(0x8000000000000), 
    geodetic=0xbfffe130, obs_pos=0xbfffe0c0, obs_vel=0xbfffe0a0)
    at sgpsdp/sgp_obs.c:39
#2  0x08055c4b in Calculate_Obs (_time=nan(0x8000000000000), pos=0xbfffe77c, 
    vel=0xbfffe79c, geodetic=0xbfffe130, obs_set=0xbfffe170)
    at sgpsdp/sgp_obs.c:111
#3  0x0809167b in predict_calc (sat=0xbfffe2e8, qth=0x81eb008, 
    t=nan(0x8000000000000)) at predict-tools.c:79
#4  0x08091b1c in find_los (sat=0xbfffe2e8, qth=0x81eb008, 
    start=1746597.485988426, maxdt=0) at predict-tools.c:290
#5  0x08091d62 in find_aos (sat=0xbfffe2e8, qth=0x81eb008, 
    start=1746597.485988426, maxdt=0) at predict-tools.c:148
#6  0x080928d0 in get_pass_no_min_el (sat_in=0xbfffe8e8, qth=0x81eb008, 
    start=1746597.485988426, maxdt=0) at predict-tools.c:893
#7  0x08092db8 in get_current_pass (sat_in=0x81d7000, qth=0x81eb008, 
    start=1746597.499988426) at predict-tools.c:1068
#8  0x0806215e in update_sat (key=0x8a158a0, value=0x81d7000, data=0x863b0f8)
    at gtk-polar-view.c:970
#9  0x0097bb44 in g_hash_table_foreach ()
   from /lib/i386-linux-gnu/libglib-2.0.so.0
#10 0x08060c08 in gtk_polar_view_update (widget=0x863b0f8)
---Type <return> to continue, or q <return> to quit---q
 at gtk-polar-view.c:6Quit
(gdb) frame 6
#6  0x080928d0 in get_pass_no_min_el (sat_in=0xbfffe8e8, qth=0x81eb008, 
    start=1746597.485988426, maxdt=0) at predict-tools.c:893
893	    aos = find_aos (sat, qth, t0, maxdt);
(gdb) print *sat_in
$1 = {name = 0x86bbae8 "ISS (ZARYA)", nickname = 0x86bbdc0 "ISS", 
  website = 0x0, tle = {epoch = 11148.148437649999, epoch_year = 2011, 
    epoch_day = 148, epoch_fod = 0.14843765, xndt2o = 7.9173104210694337e-10, 
    xndd6o = 0, bstar = 0.00017082999999999999, xincl = 0.90148524690524989, 
    xnodeo = 4.5988238913609996, eo = 0.00040630000000000001, 
    omegao = 5.9024469601002494, xmo = 1.4515205240549998, 
    xno = 0.068749899355162805, catnr = 25544, elset = 429, revnum = 71775, 
    sat_name = "00-0  37569-5 0  5913\000\000\000", idesg = "98067A  ", 
    status = 12641264, xincl1 = 0.90148524690524989, 
    xnodeo1 = -1725481.0573751149, omegao1 = -45842.032270749361}, flags = 2, 
  sgps = {aodp = 1.0538316970225836, aycof = 0.00091955980084065792, 
    c1 = 7.8611667208354887e-09, c4 = 2.9349289932220976e-06, 
    c5 = 0.0013238233243168878, cosio = 0.62044584920735901, 
    d2 = 6.2615777317740968e-15, d3 = 7.4648015255502415e-21, 
    d4 = 1.0377491637063899e-26, delmo = 1.0036785079730322, 
    omgcof = 1.4891064140824754e-06, eta = 0.01029192454200379, 
    omgdot = 4.6388693746793333e-05, sinio = 0.78424928957657281, 
    xnodp = 0.068742114485212488, sinmo = 0.99289507075378081, 
    t2cof = 1.1791750081253234e-08, t3cof = 6.3851736161996394e-15, 
    t4cof = 5.7474855734343696e-21, t5cof = 6.4167139001302717e-27, 
    x1mth2 = 0.61504694820135919, x3thm1 = 0.15485915539592257, 
    x7thm1 = 1.6946713625904861, xmcof = -0.017094870683006386, 
---Type <return> to continue, or q <return> to quit---q
xmdot = 0.068749Quit
(gdb)