Thread 4 "worker" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffeee08640 (LWP 740333)]
0x00007ffff6d959c5 in ?? () from /usr/lib/libvips.so.42
(gdb) bt
#0  0x00007ffff6d959c5 in  () at /usr/lib/libvips.so.42
#1  0x00007ffff6d862eb in  () at /usr/lib/libvips.so.42
#2  0x00007ffff6ebd582 in  () at /usr/lib/libvips.so.42
#3  0x00007ffff6ebe246 in vips_region_fill () at /usr/lib/libvips.so.42
#4  0x00007ffff6ec1fc1 in vips_region_prepare () at /usr/lib/libvips.so.42
#5  0x00007ffff6eae8ab in  () at /usr/lib/libvips.so.42
#6  0x00007ffff6ebd582 in  () at /usr/lib/libvips.so.42
#7  0x00007ffff6ebe246 in vips_region_fill () at /usr/lib/libvips.so.42
#8  0x00007ffff6ec1fc1 in vips_region_prepare () at /usr/lib/libvips.so.42
#9  0x00007ffff6eae8ab in  () at /usr/lib/libvips.so.42
#10 0x00007ffff6ebd582 in  () at /usr/lib/libvips.so.42
#11 0x00007ffff6ebe7a9 in  () at /usr/lib/libvips.so.42
#12 0x00007ffff6ec2235 in vips_region_prepare_to () at /usr/lib/libvips.so.42
#13 0x00007ffff6eb6d7a in  () at /usr/lib/libvips.so.42
#14 0x00007ffff6ec2c2c in  () at /usr/lib/libvips.so.42
#15 0x00007ffff6ec298e in  () at /usr/lib/libvips.so.42
#16 0x00007ffff6c20ec1 in  () at /usr/lib/libglib-2.0.so.0
#17 0x00007ffff79c73e9 in start_thread () at /usr/lib/libpthread.so.0
#18 0x00007ffff7ae0293 in clone () at /usr/lib/libc.so.6
(gdb)