Failed to run program parallely

I’m trying to run command “GB.f4” in GB.jl(https://github.com/ederc/GB.jl).
The command run without problems when it runs sigle thread.

julia> using GB
Welcome to Nemo version 0.16.2
Nemo comes with absolutely no warranty whatsoever

julia> R,I = GB.katsura_8(65521);

julia> H = GB.f4(I,nthrds=1);

But. when several threads, it doesn’t run, and cause segmentation fault.

julia> using GB
Welcome to Nemo version 0.16.2
Nemo comes with absolutely no warranty whatsoever

julia> R,I = GB.katsura_8(65521);

julia> H = GB.f4(I,nthrds=2);
signal (11): Segmentation fault
in expression starting at REPL[2]:1
convert_hashes_to_columns._omp_fn.22 at /home/ubuntu/.julia/packages/GB/BMo7R/deps/usr/lib/libgb.so (unknown line)
convert_hashes_to_columns at /home/ubuntu/.julia/packages/GB/BMo7R/deps/usr/lib/libgb.so (unknown line)
f4_julia at /home/ubuntu/.julia/packages/GB/BMo7R/deps/usr/lib/libgb.so (unknown line)
#f4#269 at /home/ubuntu/.julia/packages/GB/BMo7R/src/GB.jl:296
#f4 at ./none:0
unknown function (ip: 0x7fde7846e986)
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2197
do_call at /buildworker/worker/package_linux64/build/src/interpreter.c:323
eval_value at /buildworker/worker/package_linux64/build/src/interpreter.c:411
eval_stmt_value at /buildworker/worker/package_linux64/build/src/interpreter.c:362 [inlined]
eval_body at /buildworker/worker/package_linux64/build/src/interpreter.c:772
jl_interpret_toplevel_thunk_callback at /buildworker/worker/package_linux64/build/src/interpreter.c:884
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x7fde9414988f)
unknown function (ip: 0x6)
jl_interpret_toplevel_thunk at /buildworker/worker/package_linux64/build/src/interpreter.c:893
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:815
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:764
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:764
jl_toplevel_eval_in at /buildworker/worker/package_linux64/build/src/toplevel.c:844
eval at ./boot.jl:330
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2191
eval_user_input at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:86
macro expansion at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:118 [inlined]
#26 at ./task.jl:268
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2191
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1614 [inlined]
start_task at /buildworker/worker/package_linux64/build/src/task.c:596
unknown function (ip: 0xffffffffffffffff)
Allocations: 14110728 (Pool: 14108613; Big: 2115); GC: 28
Segmentation fault (コアダンプ)

I’m new to Julia and I don’t know what to do.
I’m using Julia 1.2.0., OS is Ubuntu 18.04