I've been following the git master of xorg and recently did a full reinstall, including all the libs.   At about this time, I also upgraded gv to the 3.7.3 release (actually on several machines).   gv works fin on all but the machine had the xorg rebuild.   I rebuilt with debugging symbols and traced the problem to libXt (I think), and after rebuilding that with -g I get the following backtrace (also note the warning message):

Starting program: /home/ronis/gv-3.7.3/src/gv 
Warning: Representation size 2 must match superclass's to override internalWidth

Program received signal SIGSEGV, Segmentation fault.
0xb7c07420 in main_arena () from /lib/libc.so.6
(gdb) thread apply all bt full

Thread 1 (process 29561):
#0  0xb7c07420 in main_arena () from /lib/libc.so.6
No symbol table info available.
#1  0xb7eda67c in widgetPostProc (w=0x80ec088) at Create.c:491
        insert_child = 0xb7c07420 <main_arena+160>
        parent = 0x80ebc60
        param = 0x80a919c "newtoc"
        num_params = 1
#2  0xb7eda476 in xtCreate (name=0x807dd83 "newtoc", class=0x0, 
    widget_class=0x80a18a0, parent=0x80ebc60, default_screen=0x80ab328, 
    args=0xbfffecd4, num_args=0, typed_args=0x0, num_typed_args=0, 
    parent_constraint_class=0x80a08c0, post_proc=0xb7eda59d <widgetPostProc>)
    at Create.c:434
        hookobj = 0xb7ed1853
        widget_cache = {6.1746313723954749e-270, 1.1523105039956386e-311, 0, 
          1.5914933136189803e-314, 7.2911220195563975e-304, 
          4.9406564584124654e-324, 0, 6.6790956024953092e-316, 0, 
          9.8813129168249309e-324, 6.2864522191767033e-270, 
          6.7970524130044818e-313, 5.0927898983166536e-313, 
          4.2504602880768744e-314, 1.2697487098120036e-321, 0, 
          7.2911185428784936e-304, 0, 0, 0, 8.4879831648492206e-313, 0, 0, 
          7.1515446887561504e-270, 6.6760150043803598e-316, 
          2.7814272029656453e-309, 2.1219957963999944e-314, 0, 0, 0, 0, 0, 0, 
          0, 5.6393189185391757e-270, 1.3906930471850936e-309, 
          7.0632744564452609e-304, 1.6128026351291044e-305, 
          4.9406564584124654e-324, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
          1.5914936219159434e-314, -3.3455048832928653e-39, 
          2.9181987371613227e-319, -1.9929587841013987, 
          6.836299322185737e-305, 9.8813129168249309e-322, 
          -4.7384964505192079e-39, 6.6565949636655363e-316, 
          6.6639273919154662e-316, -3.3455048832928366e-39, -1.99372103831762, 
          -3.3455048832928366e-39, -3.0438970209560045e-39, 
          6.6647554459378962e-316, -1.9938459396362305, -1.9946868119617962, 
          -2.7181543328627034e-39, -3.3455048832928366e-39, 
          7.2737491413223903e-270, -3.3455068972239873e-39, 
          -2.7165666617026443e-39, 6.1746313721530702e-270, 
          6.1638867418338061e-270, -1.9946868119617962, 
          -2.7181207016995805e-39, 6.1746338529689028e-270, 
          -3.3455068972235357e-39, 1.5914940902901756e-314, 
          -2.7181543328627348e-39, 6.1746313721389816e-270, 
          -3.3455068972235357e-39, 1.5914940902901756e-314, 
          -2.7181543328627452e-39, 6.1746313721389816e-270, 
          -2.6742113646466591e-39, -3.3455068093389609e-39, 
          -2.7181543328627556e-39, 6.1746313721389816e-270, 
          6.2589121737792593e-270, 1.5914940902901756e-314, 
          -2.7181207016996223e-39, 6.174633853393592e-270, 
          -9.5548849507197075e-40, 2.1286605000184461e-313, 
          -2.7181207016996327e-39, 6.174633853383424e-270, 
          -4.6449906065920808e-39, -3.3455048833031603e-39, 
          -2.71918708983101e-39, 6.1746313721389816e-270, 
          8.554686634694002e-314, -3.3455068972236062e-39}
        constraint_cache = {0, 2.1219957909652723e-314, 
          -5.8198279404829719e-39, -3.4765947777350059e-40, 
          8.8080179055942793e-294, 5.9415882404435826e-313, 
          -1.3472402108693015e-40, -3.386433920825939e-39, 0, 
          1.4429571378568792e-311, -3.3864339208259259e-39, 
          -2.6168362057915795e-39, 3.6465486502236558e-314, 
          -1.9935309588900028, -1.9934889970237304, -1.993473738412739, 
          -1.993462294056271, 1.5251837613254969e-314, 
          2.1219957909652723e-314, 2.1219957909652723e-314}
        req_widget = 0xbfffe4b8
        req_constraints = 0xbfffe418
        wsize = 384
        csize = 20
        widget = 0x80ec088
        cache_refs = 0x0
        i = 3086107232
        call_data = {type = 0xb7f27000 "", widget = 0x5, args = 0xbfffe4bc, 
          num_args = 3086920704}
#3  0xb7eda984 in _XtCreateWidget (name=0x807dd83 "newtoc", 
    widget_class=0x80a18a0, parent=0x80ebc60, args=0xbfffecd4, num_args=0, 
    typed_args=0x0, num_typed_args=0) at Create.c:570
        widget = 0xbfffea3c
        cwc = 0x80a08c0
        default_screen = 0x80ab328
        class_inited = 7 '\a'
        params = {0x807dd83 "newtoc", 
          0x80ebbc8 "ð½\016\bp­\016\b\220¹\016\b%\004", 0x80a9c10 ""}
        num_params = 1
#4  0xb7edaae9 in XtCreateManagedWidget (name=0x807dd83 "newtoc", 
    widget_class=0x80a18a0, parent=0x80ebc60, args=0xbfffecd4, num_args=0)
    at Create.c:610
        widget = 0xbfffea3c
        app = 0x0
#5  0x08062c09 in main (argc=1, argv=0xbfffee44) at main.c:1156
        cont_child = {0x80dd100, 0x80e46d8, 0x80e5230, 0x80e5c20, 0x80e6440, 
          0x80e65e0, 0x80e6998, 0x80e7a38, 0x80e7e40, 0x80e8208, 0x80e8640, 
          0x80e87f0, 0x80e8980, 0x80e8b10, 0x80e8cb8, 0x80e8e38, 0x80e9e00, 
          0x80e9f70, 0x80ea0e0, 0x80ea250, 0x80ea3c0, 0x80ea5b8, 0x80ea800, 
          0x80eabc0, 0x80eb990, 0xa0, 0x0, 0x0, 0x0, 0xb7a6968c, 0xb7fea362, 
          0xb7fa6000, 0x38dea, 0xb7ffeff4, 0x656290, 0xb7aaadc8, 0xb7ffafa8, 
          0xbfffecc4, 0x0, 0xb7ab3798, 0x7b1ea71, 0x3f3, 0x0, 0xf63d4e2e, 
          0xb7a778e4, 0x14, 0xb7fff900, 0x0, 0x0, 0x1}
        cont_child_num = 25
        maximum_width = <optimized out>
        maximum_height = <optimized out>
        n = 0
        dim_forced = 135074452
        args = {{name = 0x80a5094 "resize", value = 0}, {
            name = 0x80a500d "label", value = 134837670}, {
            name = 0x807bf5d "maximumWidth", value = 1260}, {
            name = 0x807bf77 "maximumHeight", value = 756}, {
            name = 0x807bf93 "minimumWidth", value = 400}, {
            name = 0x807bfad "minimumHeight", value = 430}, {
            name = 0xbfffedb4 "\216ÿw\001ôïÿ·Á©\004\b\001", 
            value = 134516212}, {
            name = 0xbfffeda8 "Lîÿ¿\230\002÷èíÿ¿\216ÿw\001ôïÿ·Á©\004\b\001", 
            value = -1207960996}, {name = 0x0, value = -1213761192}, {
            name = 0x1 <Address 0x1 out of bounds>, value = 0}, {
            name = 0x1 <Address 0x1 out of bounds>, value = -1207961344}, {
            name = 0x0, value = 0}, {name = 0x0, value = -1073746364}, {
            name = 0xb7b1608e "\201Ãfÿ\016", value = -1212129292}, {
            name = 0xb7c041e0 "", value = -1073746600}, {
            name = 0xb7abdbe5 "\213\006\205Àuõ[^]Ã\213\034$Ã", '\220' <repeats 13 times>, "U\211å]Ã\215t&", value = 0}, {name = 0x80a049c "x\003\n\b", 
            value = -1073746584}, {
            name = 0x804b55c "X[ÉÃÿ5 \004\n\bÿ%¤\004\n\b", 
            value = -1213371147}, {name = 0x80a049c "x\003\n\b", 
            value = -1073746536}, {
            name = 0x807bd59 "\215»Èþÿÿ\215\203Èþÿÿ)ÇÁÿ\002\205ÿt$1ö\213E\020\211D$\b\213E\f\211D$\004\213E\b\211\004$ÿ\224³Èþÿÿ\203Æ\001\071þrÞ\203Ä\034[^_]Ã\215¶", value = 0}}
        number = <optimized out>
        c = <optimized out>