Native Exception occurring in `bullet-native`

```
# JRE version: Java(TM) SE Runtime Environment (8.0_201-b09) (build 1.8.0_201-b09)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.201-b09 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# C  [libpthread.so.0+0xa660]  __pthread_mutex_lock+0x0
#
```