Switch to nightly rustfmt

[tnull]

Just an experiment for now.

[ldk-reviews-bot]

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[tnull]

Now disabled comment wrapping and string formatting options (TBD if we want this eventually). Rest should be good to land, IMO.

[ldk-reviews-bot]

🔔 1st Reminder

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[tnull]

Rebased to address minor conflicts.

[joostjager]

If I simply run cargo fmt, isn't that supposed to just work?

~/repo/ldk-node (2025-10-switch-to-nightly-rustfmt ✔) cargo fmt       
Warning: can't set `format_code_in_doc_comments = true`, unstable features are only available in nightly channel.
Warning: can't set `comment_width = 100`, unstable features are only available in nightly channel.

[joostjager]

I am worried now about IDE support

[tnull]

Hmm, do you happen to have set an override for LDK Node? I.e., rustup override set XXX? Otherwise it should indeed use what's inteh rust-toolchain.toml.

[tnull]

What happens in your case if you do:

?main ~/workspace/ldk-node> cargo fmt --version
rustfmt 1.8.0-stable (1159e78c47 2025-09-14)
?main ~/workspace/ldk-node> git checkout 2025-10-switch-to-nightly-rustfmt
Switched to branch '2025-10-switch-to-nightly-rustfmt'
Your branch is up to date with 'origin/2025-10-switch-to-nightly-rustfmt'.
?2025-10-switch-to-nightly-rustfmt ~/workspace/ldk-node> cargo fmt --version
rustfmt 1.8.0-nightly (f6aa851dba 2025-10-07)

[joostjager]

Ah, that was it indeed. Had been reproducing issues on older rust version with the override. All good then. Farewell to the import nits 😎