Mempool tracer without bang patterns

[jutaro]

For new tracing it is advisable/necessary to remove the strictness annotations of the tracer type.

1. These objects are guaranteed to live only very short (with the new tracing framework).
2. Their is a great probability, that these messages will be filtered out, in which case laziness is better.
3. This is of all the dozens of tracer types the only one with such strictness annotations.
4. The new tracing infrastructure works prototype based. Since it is difficult to construct these objects, we use 'undefined' to make it work, which is not possible with these strictness annotations.

[nfrisby]

Thanks for the nice PR description! LGTM.

[nfrisby]

(Edit: It looks like this worked; the Nix build is now green.)

It looks like you won the lottery with that Nix failure 👏👏👏

I have opened #3250 to look into it.

I anticipate that if we ran this PR's Hydra evals again, it wouldn't happen; I think you just got "lucky". So I'm going to try to force Hydra to do that now.

I restarted https://hydra.iohk.io/build/6835752, which had looked like this:

Your latest was https://hydra.iohk.io/build/6836123, which used a cached failure from the above. I figure Restarting that one would just use the cached failure again. So I think I restart 6835752 and then once it finishes restart 6836123 and then we'll be green 🤞

[EncodePanda]

This PR is now green, should we merge it? @nfrisby @jutaro

[jutaro]

Yes, please merge

[nfrisby]

@jutaro Would you rebase it? I expect that git fetch origin; git rebase -i origin/master will work without conflicts. Then we can invoke bors to merge it. Thanks!

[jutaro]

I have done the rebasing

[nfrisby]

bors r+

[iohk-bors]

Build failed:

• buildkite/ouroboros-network

[deepfire]

bors r+

[iohk-bors]

Build succeeded:

• ci/hydra:Cardano:ouroboros-network:required
• buildkite/ouroboros-network