There's a patch attached that seems to fix the problem.
% lynx
lynx(52571,0x7fff7d6e7300) malloc: *** error for object 0x7fa0a0d01911: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
zsh: abort lynx
% lldb lynx
(lldb) target create "lynx"
Current executable set to 'lynx' (x86_64).
(lldb) run
Process 52580 launched: '/usr/local/bin/lynx' (x86_64)
lynx(52580,0x7fff7d6e7300) malloc: *** error for object 0x100400ef1: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Process 52580 stopped
* thread #1: tid = 0x91a4f6, 0x00007fff8c618286 libsystem_kernel.dylib`__pthread_kill + 10, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
frame #0: 0x00007fff8c618286 libsystem_kernel.dylib`__pthread_kill + 10
libsystem_kernel.dylib`__pthread_kill:
-> 0x7fff8c618286 <+10>: jae 0x7fff8c618290 ; <+20>
0x7fff8c618288 <+12>: movq %rax, %rdi
0x7fff8c61828b <+15>: jmp 0x7fff8c613c53 ; cerror_nocancel
0x7fff8c618290 <+20>: retq
(lldb) bt
* thread #1: tid = 0x91a4f6, 0x00007fff8c618286 libsystem_kernel.dylib`__pthread_kill + 10, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
* frame #0: 0x00007fff8c618286 libsystem_kernel.dylib`__pthread_kill + 10
frame #1: 0x00007fff9a4e242f libsystem_pthread.dylib`pthread_kill + 90
frame #2: 0x00007fff933bdb53 libsystem_c.dylib`abort + 129
frame #3: 0x00007fff90a46937 libsystem_malloc.dylib`free + 428
frame #4: 0x0000000100054f48 lynx`LYsetRcValue + 841
frame #5: 0x00000001000551ba lynx`read_rc + 356
frame #6: 0x0000000100026676 lynx`main + 2388
frame #7: 0x000000010000119c lynx`start + 52
(lldb) ^D
% lynx --version
Lynx Version 2.8.9dev.6 (06 May 2015)
libwww-FM 2.14, SSL-MM 1.4.1, OpenSSL 0.9.8zd, ncurses 5.7.20081102
Criado em darwin14.3.0 May 27 2015 13:30:59
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