Seems that rust-tonic is currently not installable in sid:

The following packages have unmet dependencies:
 librust-tonic-dev : Depends: librust-rustls-native-certs-0.6+default-dev but it is not installable
E: Unable to correct problems, you have held broken packages.
E: The following information from --solver 3.0 may provide additional context:
   Unable to satisfy dependencies. Reached two conflicting decisions:
   1. util-linux:amd64 is selected for install
   2. util-linux:amd64 is available in versions 2.41.1-2, 2.41.1-1
      but none of the choices are installable:
      - util-linux:amd64=2.41.1-2 PreDepends libblkid1 (= 2.41.1-2)
        but none of the choices are installable:
        - libblkid1:amd64=2.41.1-2 ->  | libblkid1:amd64
          but none of the choices are installable:
          - libblkid1:amd64 is selected for removal
      - util-linux:amd64=2.41.1-1 is not selected for install
apt-get failed.
E: Package installation failed

I've prepared an NMU at https://salsa.debian.org/debian/rust-tonic/-/commits/debian/wip-native-certs-0.8 for your cenvenience.

<#part type="text/x-diff" filename="/tmp/nmu.diff" disposition=attachment>
<#/part>

Quoting Reinhard Tartler (2025-08-31 03:12:33)

Yes, I deliberately broke it yesterday...
build what I had prepared myself. :-)

 - Jonas

We believe that the bug you reported is fixed in the latest version of
rust-tonic, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1112560@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Jonas Smedegaard <dr@jones.dk> (supplier of updated rust-tonic package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sun, 31 Aug 2025 09:52:35 +0200
Source: rust-tonic
Architecture: source
Version: 0.12.3+dfsg-5
Distribution: unstable
Urgency: medium
Maintainer: Jonas Smedegaard <dr@jones.dk>
Changed-By: Jonas Smedegaard <dr@jones.dk>
Closes: 1112560
Changes:
 rust-tonic (0.12.3+dfsg-5) unstable; urgency=medium
 .
   * drop obsolete patches 2001_rustls-native-certs_*;
     bump (build-)dependencies for crate rustls-native-certs;
     closes: bug#1112560, thanks to Reinhard Tartler
   * update watch file:
     + use file format version 5
     + improve mangling of upstream version
   * update DEP-3 patch headers
   * rename patch 2001_tower-http -> 1001_tower-http
Checksums-Sha1:
 56dd85cc32bdb82f0ace50fed34a1f88a9095a04 5632 rust-tonic_0.12.3+dfsg-5.dsc
 234857a0858cc423eba80ff026a6fb6c28ff0362 12392 rust-tonic_0.12.3+dfsg-5.debian.tar.xz
 77bc9efb4b758a617d9b5c58ecdc5f0737f2d90d 21367 rust-tonic_0.12.3+dfsg-5_amd64.buildinfo
Checksums-Sha256:
 c3b3dabc46bc9f02e5bd7795dae88fa1c90080da1272a10ab3633147dd33d0b2 5632 rust-tonic_0.12.3+dfsg-5.dsc
 997093d8094d2ca39c185bc15e39137454decedd17f16b33bb588a909f2bb54f 12392 rust-tonic_0.12.3+dfsg-5.debian.tar.xz
 ce42c5f6b7cd504a40b072bf193bb0479863cf776470861fda08dcfc943cd06d 21367 rust-tonic_0.12.3+dfsg-5_amd64.buildinfo
Files:
 ffef7b3418ea77703891f4c54f9af557 5632 rust optional rust-tonic_0.12.3+dfsg-5.dsc
 8888e79f8fe220fe1dbc1efdc3a16edd 12392 rust optional rust-tonic_0.12.3+dfsg-5.debian.tar.xz
 7eb1833cfbb068876524bbcf7642c3dd 21367 rust optional rust-tonic_0.12.3+dfsg-5_amd64.buildinfo
-----BEGIN PGP SIGNATURE-----
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=yPgA
-----END PGP SIGNATURE-----