1. 1. Summary

On arm64 (Raspberry Pi 5, Cortex-A76 / ARMv8.2-A), `mongod` from the official image starts, runs for a short time, then dies with *SIGSEGV* (`docker events` shows `die exitCode=139`) and loops forever under a restart policy. No graceful shutdown and no fatal log line is emitted; the next start just reports "Detected unclean shutdown."

Bisecting the published tags gives a clean boundary: *`8.0.4` is the last good release; `8.0.5` is the first that crash-loops*, and every release after it (8.0.6 → 8.0.26, all 8.2.x, all 8.3.x, `latest`) is affected.

1. 1. Reproduction

```bash
docker run --rm mongo:8.0.5     # SIGSEGV (exit 139), crash-loops roughly every ~30s
docker run --rm mongo:8.0.4     # runs fine
```

No app, config, replica set, or volumes required — a bare `docker run` reproduces it. To watch the crash:

```bash
docker events --filter image=mongo:8.0.5 --filter event=die \
  --format '.Time exit=.Actor.Attributes.exitCode'
```

1. 1. Bisect (one standalone container per version)

There is no published 8.0.2 or 8.0.7, so `8.0.4 → 8.0.5` is the exact consecutive boundary in the official images.

1. 1. Environment

• Image: official `library/mongo`, tags `8.0.5`+ (build: `allocator: tcmalloc-google`, `distmod: ubuntu2404`, `distarch: aarch64`)
• Host: Raspberry Pi 5, Cortex-A76 (ARMv8.2-A), Ubuntu kernel `7.0.0-1010-raspi`, page size 4096
• Docker 29.5.1

1. 1. Details

• Exit is *139 = SIGSEGV*; no backtrace and no shutdown sequence is logged before death.
• `GLIBC_TUNABLES=glibc.pthread.rseq=0` (from #723) is present in the container env and does not prevent it.
• Not OOM (`State.OOMKilled=false`, `memory.events: oom_kill 0`). Not the older Pi 4 "Illegal instruction"/SIGILL case (#510, #508, #485) — this CPU is ARMv8.2-A and the signal is SIGSEGV, and 8.0.4 on the same host is stable.