Hope this is a stacktrace. ;-)
0x0000000100170b10 <+0000> push %rbp
0x0000000100170b11 <+0001> mov %rsp,%rbp
0x0000000100170b14 <+0004> push %r15
0x0000000100170b16 <+0006> push %r14
0x0000000100170b18 <+0008> push %rbx
0x0000000100170b19 <+0009> sub $0x38,%rsp
0x0000000100170b1d <+0013> mov %rdx,%r14
0x0000000100170b20 <+0016> mov %rdi,%r15
0x0000000100170b23 <+0019> lea -0x48(%rbp),%rdi
0x0000000100170b27 <+0023> callq 0x100177884 <dyld_stub__ZNSsC1ERKSs>
0x0000000100170b2c <+0028> mov -0x48(%rbp),%rax
0x0000000100170b30 <+0032> cmpl $0x0,-0x8(%rax)
0x0000000100170b34 <+0036> mov %rax,%rbx
0x0000000100170b37 <+0039> js 0x100170b50 <_ZN2sf4Http7Request8setFieldERKSsS3_+64>
0x0000000100170b39 <+0041> lea -0x48(%rbp),%rdi
0x0000000100170b3d <+0045> callq 0x10017782a <dyld_stub__ZNSs12_M_leak_hardEv>
0x0000000100170b42 <+0050> mov -0x48(%rbp),%rax
0x0000000100170b46 <+0054> mov %rax,%rbx
0x0000000100170b49 <+0057> nopl 0x0(%rax)
0x0000000100170b50 <+0064> cmpl $0x0,-0x8(%rax)
0x0000000100170b54 <+0068> js 0x100170b63 <_ZN2sf4Http7Request8setFieldERKSsS3_+83>
0x0000000100170b56 <+0070> lea -0x48(%rbp),%rdi
0x0000000100170b5a <+0074> callq 0x10017782a <dyld_stub__ZNSs12_M_leak_hardEv>
0x0000000100170b5f <+0079> mov -0x48(%rbp),%rax
0x0000000100170b63 <+0083> add -0x18(%rax),%rax
0x0000000100170b67 <+0087> cmp %rax,%rbx
0x0000000100170b6a <+0090> je 0x100170b7f <_ZN2sf4Http7Request8setFieldERKSsS3_+111>
0x0000000100170b6c <+0092> movsbl (%rbx),%edi
0x0000000100170b6f <+0095> callq 0x100177728 <dyld_stub___tolower>
0x0000000100170b74 <+0100> mov %al,(%rbx)
0x0000000100170b76 <+0102> inc %rbx
0x0000000100170b79 <+0105> mov -0x48(%rbp),%rax
0x0000000100170b7d <+0109> jmp 0x100170b50 <_ZN2sf4Http7Request8setFieldERKSsS3_+64>
0x0000000100170b7f <+0111> lea -0x40(%rbp),%rdi
0x0000000100170b83 <+0115> lea -0x48(%rbp),%rsi
0x0000000100170b87 <+0119> callq 0x100177884 <dyld_stub__ZNSsC1ERKSs>
0x0000000100170b8c <+0124> lea -0x40(%rbp),%rsi
0x0000000100170b90 <+0128> mov %r15,%rdi
0x0000000100170b93 <+0131> callq 0x1001730c0
0x0000000100170b98 <+0136> mov %rax,%rdi <= Here it shows me Signal receipt "SIGABRT"
0x0000000100170b9b <+0139> mov %r14,%rsi
0x0000000100170b9e <+0142> callq 0x10017785a <dyld_stub__ZNSs6assignERKSs>
0x0000000100170ba3 <+0147> mov -0x40(%rbp),%rdi
0x0000000100170ba7 <+0151> mov $0xffffffff,%ebx
0x0000000100170bac <+0156> mov $0xffffffff,%eax
0x0000000100170bb1 <+0161> lock xadd %eax,-0x8(%rdi)
0x0000000100170bb6 <+0166> test %eax,%eax
0x0000000100170bb8 <+0168> jg 0x100170bc7 <_ZN2sf4Http7Request8setFieldERKSsS3_+183>
0x0000000100170bba <+0170> add $0xffffffffffffffe8,%rdi
0x0000000100170bbe <+0174> lea -0x38(%rbp),%rsi
0x0000000100170bc2 <+0178> callq 0x100177836 <dyld_stub__ZNSs4_Rep10_M_destroyERKSaIcE>
0x0000000100170bc7 <+0183> mov -0x48(%rbp),%rdi
0x0000000100170bcb <+0187> lock xadd %ebx,-0x8(%rdi)
0x0000000100170bd0 <+0192> test %ebx,%ebx
0x0000000100170bd2 <+0194> jg 0x100170be1 <_ZN2sf4Http7Request8setFieldERKSsS3_+209>
0x0000000100170bd4 <+0196> add $0xffffffffffffffe8,%rdi
0x0000000100170bd8 <+0200> lea -0x30(%rbp),%rsi
0x0000000100170bdc <+0204> callq 0x100177836 <dyld_stub__ZNSs4_Rep10_M_destroyERKSaIcE>
0x0000000100170be1 <+0209> add $0x38,%rsp
0x0000000100170be5 <+0213> pop %rbx
0x0000000100170be6 <+0214> pop %r14
0x0000000100170be8 <+0216> pop %r15
0x0000000100170bea <+0218> pop %rbp
0x0000000100170beb <+0219> retq
0x0000000100170bec <+0220> mov %rax,%rbx
0x0000000100170bef <+0223> jmp 0x100170c18 <_ZN2sf4Http7Request8setFieldERKSsS3_+264>
0x0000000100170bf1 <+0225> mov %rax,%rbx
0x0000000100170bf4 <+0228> jmp 0x100170c18 <_ZN2sf4Http7Request8setFieldERKSsS3_+264>
0x0000000100170bf6 <+0230> mov %rax,%rbx
0x0000000100170bf9 <+0233> mov -0x40(%rbp),%rdi
0x0000000100170bfd <+0237> mov $0xffffffff,%eax
0x0000000100170c02 <+0242> lock xadd %eax,-0x8(%rdi)
0x0000000100170c07 <+0247> test %eax,%eax
0x0000000100170c09 <+0249> jg 0x100170c18 <_ZN2sf4Http7Request8setFieldERKSsS3_+264>
0x0000000100170c0b <+0251> add $0xffffffffffffffe8,%rdi
0x0000000100170c0f <+0255> lea -0x28(%rbp),%rsi
0x0000000100170c13 <+0259> callq 0x100177836 <dyld_stub__ZNSs4_Rep10_M_destroyERKSaIcE>
0x0000000100170c18 <+0264> mov -0x48(%rbp),%rdi
0x0000000100170c1c <+0268> mov $0xffffffff,%eax
0x0000000100170c21 <+0273> lock xadd %eax,-0x8(%rdi)
0x0000000100170c26 <+0278> test %eax,%eax
0x0000000100170c28 <+0280> jg 0x100170c37 <_ZN2sf4Http7Request8setFieldERKSsS3_+295>
0x0000000100170c2a <+0282> add $0xffffffffffffffe8,%rdi
0x0000000100170c2e <+0286> lea -0x20(%rbp),%rsi
0x0000000100170c32 <+0290> callq 0x100177836 <dyld_stub__ZNSs4_Rep10_M_destroyERKSaIcE>
0x0000000100170c37 <+0295> mov %rbx,%rdi
0x0000000100170c3a <+0298> callq 0x10017770a <dyld_stub__Unwind_Resume>
0x0000000100170c3f <+0303> nop
regards
Mike