this is darktable 1.6.4 reporting a segfault:

#0  0x00007f0d30749ee9 in waitpid () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007f0d309e06b0 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
#2  <signal handler called>
#3  0x00007f0d30a1e4bd in dt_mipmap_cache_allocate () from /usr/bin/../lib/darktable/libdarktable.so
#4  0x00007f0d309d4a9a in dt_cache_read_get () from /usr/bin/../lib/darktable/libdarktable.so
#5  0x00007f0d30a1f239 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
#6  0x00007f0d309e2f39 in dt_init () from /usr/bin/../lib/darktable/libdarktable.so
#7  0x00000000004007e0 in main ()

Thread 6 (Thread 0x7f0d23cb6700 (LWP 32114)):
#0  0x00007f0d30746414 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007f0d30a3c9e6 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#2  0x00007f0d30742182 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#3  0x00007f0d3046f47d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.

Thread 5 (Thread 0x7f0d234b5700 (LWP 32115)):
#0  0x00007f0d30746414 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007f0d30a3c9e6 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#2  0x00007f0d30742182 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#3  0x00007f0d3046f47d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.

Thread 4 (Thread 0x7f0d22cb4700 (LWP 32116)):
#0  0x00007f0d30435f3d in nanosleep () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
#1  0x00007f0d30435dd4 in sleep () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
#2  0x00007f0d30a3bb3a in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#3  0x00007f0d30742182 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#4  0x00007f0d3046f47d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.

Thread 3 (Thread 0x7f0d224b3700 (LWP 32117)):
#0  0x00007f0d30746414 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007f0d30a3beae in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#2  0x00007f0d30742182 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#3  0x00007f0d3046f47d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.

Thread 2 (Thread 0x7f0d21cb2700 (LWP 32118)):
#0  0x00007f0d30746414 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007f0d30a3beae in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#2  0x00007f0d30742182 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#3  0x00007f0d3046f47d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.

Thread 1 (Thread 0x7f0d31052a40 (LWP 32113)):
#0  0x00007f0d30749ee9 in waitpid () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007f0d309e06b0 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#2  <signal handler called>
No symbol table info available.
#3  0x00007f0d30a1e4bd in dt_mipmap_cache_allocate () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#4  0x00007f0d309d4a9a in dt_cache_read_get () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#5  0x00007f0d30a1f239 in ?? () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#6  0x00007f0d309e2f39 in dt_init () from /usr/bin/../lib/darktable/libdarktable.so
No symbol table info available.
#7  0x00000000004007e0 in main ()
No symbol table info available.