1.19-2 segfaults on all architectures

1.19-2 segfaults on all architectures. I'm getting this from valgrind:

1: ==8494== Process terminating with default action of signal 11 (SIGSEGV)
1: ==8494== Access not within mapped region at address 0x61632F6D6F6347
1: ==8494== at 0x4EB5804: leveldb::InternalFilterPolicy::CreateFilter(leveldb::Slice const*, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4ECBBAF: leveldb::FilterBlockBuilder::GenerateFilter() (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4ECBD87: leveldb::FilterBlockBuilder::StartBlock(unsigned long) (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4ED1F8F: leveldb::TableBuilder::Flush() (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4ED2113: leveldb::TableBuilder::Add(leveldb::Slice const&, leveldb::Slice const&) (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4EA68AB: leveldb::BuildTable(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, leveldb::Env*, leveldb::Options const&, leveldb::TableCache*, leveldb::Iterator*, leveldb::FileMetaData*) (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4EAD183: leveldb::DBImpl::WriteLevel0Table(leveldb::MemTable*, leveldb::VersionEdit*, leveldb::Version*) (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4EAEECF: leveldb::DBImpl::CompactMemTable() (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4EAFD3F: leveldb::DBImpl::BackgroundCompaction() (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4EB051F: leveldb::DBImpl::BackgroundCall() (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x4ED7C3B: ??? (in /usr/lib/aarch64-linux-gnu/libleveldb.so.1.19)
1: ==8494== by 0x53E901B: start_thread (pthread_create.c:335)

The code using leveldb has been stable for more than a year and works perfectly on vivid, xenial, and zesty. With leveldb 1.18-5, I can run the tests for days on end without any problems. The instant is install 1.19-2, I get segfaults.

See https://bugs.launchpad.net/ubuntu/+source/thumbnailer/+bug/1640326