back-edge from insn 517 to 486 -- from a filter that used to work

I have a filter that *used* to work -- it does have a couple of small loops (6 iterations) and it does have

```
#pragma (unroll)
```

at the top. This works when I use this version on libbcc:

```
$ file /usr/lib64/libbcc.so.0.10.0
/usr/lib64/libbcc.so.0.10.0: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, BuildID[sha1]=c7823b836d559c0eea1679f0c1edde9e88cbaf2d, not stripped
$ uname -a
Linux ip-172-17-110-17.ame1.bitsighttech.com 4.14.143-118.123.amzn2.x86_64 #1 SMP Thu Sep 12 16:54:23 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
```

However, this version gives the back-edge error:

```
# file /usr/lib/x86_64-linux-gnu/libbcc.so.0.10.0
/usr/lib/x86_64-linux-gnu/libbcc.so.0.10.0: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, BuildID[sha1]=cbe27cfa9de373afc40d1497c43f4859d63d4802, stripped
# uname -a
Linux greac4a10e8 4.15.0-66-generic #75~16.04.1-Ubuntu SMP Tue Oct 1 14:01:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
```

Is there a way that I can find the actual versions (or commit hashes) that the two versions were built from? I suspect that the second (non-working) version was installed using the prebuilt ubuntu package a few days ago. The ubuntu package at around Christmas time worked.