cannot install libssl-dev due to phased updates?

[Marius Gedminas]

I have two Vagrant boxes: one with Ubuntu 18.04 LTS, one with Ubuntu 20.04 LTS. Both currently refuse to install libssl-dev for me:

vagrant@ubuntu2004:~$ sudo apt install libssl-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libssl-dev : Depends: libssl1.1 (= 1.1.1f-1ubuntu2.4) but 1.1.1f-1ubuntu2.5 is to be installed
E: Unable to correct problems, you have held broken packages.

vagrant@ubuntu2004:~$ apt policy libssl-dev
libssl-dev:
  Installed: (none)
  Candidate: 1.1.1f-1ubuntu2.4
  Version table:
     1.1.1f-1ubuntu2.4 500
        500 http://lt.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     1.1.1f-1ubuntu2.3 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     1.1.1f-1ubuntu2 500
        500 http://lt.archive.ubuntu.com/ubuntu focal/main amd64 Packages

vagrant@ubuntu2004:~$ apt policy libssl1.1
libssl1.1:
  Installed: 1.1.1f-1ubuntu2.5
  Candidate: 1.1.1f-1ubuntu2.5
  Version table:
 *** 1.1.1f-1ubuntu2.5 100
        100 /var/lib/dpkg/status
     1.1.1f-1ubuntu2.4 500
        500 http://lt.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     1.1.1f-1ubuntu2.3 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     1.1.1f-1ubuntu2 500
        500 http://lt.archive.ubuntu.com/ubuntu focal/main amd64 Packages

(The 18.04 box is in a similar situation.)

packages.ubuntu.com says that libssl1.1 1.1.1f-1ubuntu2.5 is the current version available in focal-updates. I'm pretty sure my VM here doesn't see it because of apt's phased updates (but I only know this because I'm following the blogs on Planet Ubuntu; the error message give no clue!).

I have no idea how to resolve this in a generic way (it's an Ansible playbook that fails for me). As a manual fix, I suppose I could downgrade libssl1.1 to 1.1.1f-1ubuntu2.4, but I don't want to hardcode specific version numbers -- I expect 1.1.1f-1ubuntu2.5 will be available universally some time soon?

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: apt 2.0.6
ProcVersionSignature: Ubuntu 5.4.0-80.90-generic 5.4.124
Uname: Linux 5.4.0-80-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.18
Architecture: amd64
CasperMD5CheckResult: skip
Date: Mon Aug 23 07:08:34 2021
InstallationDate: Installed on 2021-08-11 (11 days ago)
InstallationMedia: Ubuntu-Server 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: apt
UpgradeStatus: No upgrade log present (probably fresh install)

[Marius Gedminas (mgedmin)]

On a closer look it may just be a mirror inconsistency.

There's no Phased-Update-Percentage field in /var/lib/apt/lists/lt.archive.ubuntu.com_ubuntu_dists_focal-updates_main_binary-amd64_Packages for the libssl-dev entry, and the only available version is 1.1.1f-1ubuntu2.4.

[Marius Gedminas (mgedmin)]

https://launchpad.net/ubuntu/+archivemirrors shows four mirrors in Lithuania, all "up to date".

Two of them actually are. One (Vilnius University) has a focal-updates/Packages.gz from 2021-05-04 with libssl-dev version 1.1.1f-1ubuntu2.3, one (LitNET) has a focal-updates/Packages.gz from 2021-07-29 with libssl-dev version 1.1.1f-1ubuntu2.4.