The gdb output: Thread 1 "netsurf" received signal SIGSEGV, Segmentation fault. 0x0000000082000bff in ?? () (gdb) bt #0 0x0000000082000bff in ?? () #1 0x00007ffff3617406 in ?? () from /usr/lib/x86_64-linux- gnu/libssl.so.1.0.2 #2 0x00007ffff752988a in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #3 0x00007ffff7529e0a in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #4 0x00007ffff752e1e2 in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #5 0x00007ffff74df5d2 in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #6 0x00007ffff74f2417 in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #7 0x00007ffff7507716 in ?? () from /usr/lib/x86_64-linux- gnu/libcurl.so.4 #8 0x00007ffff7508641 in curl_multi_perform () from /usr/lib/x86_64- linux-gnu/libcurl.so.4 #9 0x00000000004d0d98 in ?? () #10 0x00000000004cd11d in fetch_fdset () #11 0x0000000000552e60 in ?? () #12 0x00000000004536f3 in main ()