This package still is not installable after the build due to the same broken dependencies that got it orphaned / retired in the first place:
https://bugzilla.redhat.com/show_bug.cgi?id=2006269

Error: 
 Problem 1: conflicting requests
  - nothing provides crate(signature_derive/default) = 1.0.0~pre.4 needed by rust-signature+signature_derive-devel-1.5.0-1.fc37.noarch
 Problem 2: package rust-signature+derive-preview-devel-1.5.0-1.fc37.noarch requires crate(signature/signature_derive) = 1.5.0, but none of the providers can be installed
  - conflicting requests
  - nothing provides crate(signature_derive/default) = 1.0.0~pre.4 needed by rust-signature+signature_derive-devel-1.5.0-1.fc37.noarch

I recommend that you use "--postinstall" argument for mock when you build packages locally to catch such problems early.

There are two options to solve this:

1. disable the (disabled-by-default) derive feature and remove the (optional) signature_derive dependency.

This assumes that the package you want to package the "signature" crate for does not actually *use* this feature.

2. package the signature_derive crate.

I went with #2 since rust2rpm output seems to work out of the box.  bz#2118080

Please update to the latest release (1.6.4 as of time of writing) and refresh the packaging with rust2rpm v22.

Spec URL: https://gathman.org/linux/SPECS/rust-signature.spec
SRPM URL: https://gathman.org/linux/f37/src/rust-signature-1.6.4-1.fc37.src.rpm

Are these warnings normal?
RPM build warnings:
    File listed twice: /usr/share/cargo/registry/signature-1.6.4/CHANGELOG.md
    File listed twice: /usr/share/cargo/registry/signature-1.6.4/LICENSE-APACHE
    File listed twice: /usr/share/cargo/registry/signature-1.6.4/LICENSE-MIT
    File listed twice: /usr/share/cargo/registry/signature-1.6.4/README.md

Yes, these warnings are harmless, and can be ignored.
The built packages will contain the correct files, and the correct files will be marked as %doc and %license, respectively.
This change was implemented in rust2rpm to make RPM packages for Rust crates smaller by not including these files twice.

I rebuilt with --postinstall after build new rust-signature_derive-1.0.0-pre.7

Package was generated with rust2rpm, simplifying the review.

- package builds and installs without errors on rawhide
- test suite is run and all unit tests pass (there are no tests)
- latest version of the crate is packaged
- license matches upstream specification (Apache-2.0 OR MIT) and is acceptable for Fedora
- license files are included with %license in %files
- package complies with Rust Packaging Guidelines

Package APPROVED.

===

Recommended post-import rust-sig tasks:

- add @rust-sig with "commit" access as package co-maintainer

- set bugzilla assignee overrides to @rust-sig (optional)

===

You can proceed with the package unretirement process now.
Please also request unretirement for the f36 and f37 branches.

I resubmitted the failed rawhide build:
https://bodhi.fedoraproject.org/updates/FEDORA-2022-8c70c1eba4