(gdb) bt
#0  0x00007ffff3baf69b in raise () from /lib64/libc.so.6
#1  0x00007ffff3bb14a0 in abort () from /lib64/libc.so.6
#2  0x00007ffff17164e6 in mdb_assert_fail (env=0x7fffd8000930,
    expr_txt=0x7ffff171a6cc "rc == 0", func=0x7ffff171a9b0 <__func__.6076> "mdb_page_dirty",
    file=0x7ffff171a6a8 "../src/lmdb/libraries/liblmdb/mdb.c", line=2386)
    at ../src/lmdb/libraries/liblmdb/mdb.c:1758
#3  0x00007ffff16b0e1f in mdb_page_dirty (txn=0x7fffd81084c0, mp=0x7fffcc1b7810)
    at ../src/lmdb/libraries/liblmdb/mdb.c:2386
#4  0x00007ffff16b137f in mdb_page_alloc (mc=0x7fffcc045af0, num=1, mp=0x7fffe3ffe568)
    at ../src/lmdb/libraries/liblmdb/mdb.c:2590
#5  0x00007ffff16b177a in mdb_page_touch (mc=0x7fffcc045af0)
    at ../src/lmdb/libraries/liblmdb/mdb.c:2709
#6  0x00007ffff16b86a1 in mdb_cursor_touch (mc=0x7fffcc045af0)
    at ../src/lmdb/libraries/liblmdb/mdb.c:7328
#7  0x00007ffff16ba420 in mdb_cursor_del (mc=0x7fffcc045af0, flags=0)
    at ../src/lmdb/libraries/liblmdb/mdb.c:7885