v1.18: Improves panic message if send() fails in streaming_unpack_snapshot() (backport of #2459)

[mergify]

Problem

There are reports on Discord¹² of people hitting panics while sending on a channel during snapshot unpacking. Here's an example:

thread 'solUnpkSnpsht01' panicked at /var/lib/buildkite-agent/builds/release/anza/agave-secondary/accounts-db/src/hardened_unpack.rs:338:45:
called `Result::unwrap()` on an `Err` value: "SendError(..)"
stack backtrace:

The unwrap doesn't yield the best panic message...

Summary of Changes

Improve the panic message.

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This is an automatic backport of pull request #2459 done by Mergify.

Backport Reasoning

I'd like to backport this so we have a better panic message. Maybe this help elucidate why some people have been hitting this panic. Minimally I'd like to have the path information the new message provides.

If we do not backport, we'd have to wait until v2.1 before we could get any additional information.

This backport does not change any behavior, just expands the logging.

Footnotes

1. https://discord.com/channels/428295358100013066/560174212967432193/1270412894026207305 ↩

2. https://discord.com/channels/428295358100013066/837340113067049050/1270052679309328408 ↩

[steviez]

Noticed I never reviewed this - given that we figured out what the problem was for those nodes (v1.18 nodes trying to consume v2.1 snaps), I don't think it is as critical to BP this. Wdyt ?

[brooksprumo]

Noticed I never reviewed this - given that we figured out what the problem was for those nodes (v1.18 nodes trying to consume v2.1 snaps), I don't think it is as critical to BP this. Wdyt ?

Yeah, once we figured out the problem it became less important for this backport. Although this is the only version that would've benefitted from the code changes 🙃

I'll close it. We can always reopen it later if we need.