In case it helps, hereâs the last part of strace with the same command. The last mmap seems to be asking for 0x10000001000 bytes.
stat("/home/peter/src/pykythe/pykythe", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat("/home/peter/src/pykythe/pykythe/pykythe_utils.pl", {st_mode=S_IFREG|0644, st_size=19005, ...}) = 0
access("/home/peter/src/pykythe/pykythe/pykythe_utils.pl", R_OK) = 0
stat("/home/peter/src/pykythe/pykythe", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
read(5, "a1Hex),\n SrcSha1Hex == Sh"..., 4096) = 2276
futex(0x7fca622d37d8, FUTEX_WAKE_PRIVATE, 1) = 1
close(5) = 0
clock_gettime(0xfffeb2a6 /* CLOCK_??? */, {tv_sec=0, tv_nsec=194220467}) = 0
read(4, "nches).\n:- style_check(+no_effec"..., 4096) = 4096
stat("/home/peter/src/pykythe/pykythe/rdet2.pl", {st_mode=S_IFREG|0644, st_size=3002, ...}) = 0
access("/home/peter/src/pykythe/pykythe/rdet2.pl", R_OK) = 0
stat("/home/peter/src/pykythe/pykythe", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
read(4, " kyfacts_signature_node/5,\n "..., 4096) = 4096
rt_sigprocmask(SIG_BLOCK, ~[QUIT BUS SEGV CONT STOP PROF RTMIN RT_1], [], 8) = 0
clock_gettime(0xfffeb2a6 /* CLOCK_??? */, {tv_sec=0, tv_nsec=195165735}) = 0
mmap(NULL, 401408, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fca625c5000
munmap(0x7fca62627000, 335872) = 0
clock_gettime(0xfffeb2a6 /* CLOCK_??? */, {tv_sec=0, tv_nsec=195403868}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
clock_gettime(0xfffeb2a6 /* CLOCK_??? */, {tv_sec=0, tv_nsec=195796708}) = 0
rt_sigprocmask(SIG_BLOCK, ~[QUIT BUS SEGV CONT STOP PROF RTMIN RT_1], [], 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
clock_gettime(0xfffeb2a6 /* CLOCK_??? */, {tv_sec=0, tv_nsec=195944439}) = 0
mmap(NULL, 1099511631872, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory)
write(2, "[FATAL ERROR: at Fri Aug 21 12:5"..., 43) = 43
write(2, "Could not allocate memory: Canno"..., 49) = 49
write(2, "]\n", 2) = 2
futex(0x7fca622d37dc, FUTEX_WAKE_PRIVATE, 1) = 1
nanosleep({tv_sec=0, tv_nsec=100000000}, 0x7fff2a054e00) = 0
close(4) = 0
rt_sigaction(SIGHUP, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGINT, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGQUIT, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGILL, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGABRT, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGFPE, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGSEGV, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGALRM, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGTERM, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGUSR2, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGBUS, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGXCPU, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGXFSZ, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigaction(SIGVTALRM, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, {sa_handler=0x7fca61fe9880, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7fca61b8bfd0}, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [ABRT], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
getpid() = 10667
gettid() = 10667
tgkill(10667, 10667, SIGABRT) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
--- SIGABRT {si_signo=SIGABRT, si_code=SI_TKILL, si_pid=10667, si_uid=1000} ---
+++ killed by SIGABRT (core dumped) +++
. As we have this now anyway and this seems a better starting point for further improvements it is probably worth continuing from here.