#1137655 fish: FTBFS once rust-lru 0.16 lands; Build-Depends too loose

Package:
fish
Source:
fish
Description:
friendly interactive shell
Submitter:
Juan M. Méndez Rey
Date:
2026-05-26 13:41:02 UTC
Severity:
normal
#1137655#5
Date:
2026-05-26 13:37:47 UTC
From:
To:
I am upgrading rust-lru here:
https://salsa.debian.org/rust-team/debcargo-conf/-/merge_requests/1139

And while running ratt, discovered that fish's d/control has `Build-Depends: librust-lru-dev` (unversioned), but upstream Cargo.toml pins `lru = "^0.12"`.

With the pending rust-lru 0.16.4 upload, apt will install librust-lru-dev=0.16.4 and Cargo fails with ratt.

error: failed to select a version for the requirement `lru = "^0.12"`

Confirmed by ratt --direct-rdeps + --recheck: fish builds fine today,
FTBFS the moment rust-lru 0.16.x lands.

The Fix can be:
Build-Depends: librust-lru-0.12+default-dev (probably the easiest)
or
Update fish to lru 0.16 (small API changes only)

Thanks,
Juan