Qgis from https://qgis.org/ubuntu-ltr not installable on Ubuntu 18.04

[qgib]

Author Name: Augustin Trancart (Augustin Trancart)
Original Redmine Issue: 21568
Affected QGIS version: 3.4.5
Redmine category:build/install

---

[Description]

Qgis installation fails on ubuntu 18.04 using ubuntu-ltr ppa

[steps]

• add "deb https://qgis.org/ubuntu-ltr bionic main" to source list.
• run "sudo apt install qgis"

[Result]

the installation fails. Here is the relevant part of the logs

 Setting up qgis-providers (1:3.4.5+28bionic) ...
/usr/lib/qgis/crssync: error while loading shared libraries: libwebp.so.5: cannot open shared object file: No such file or directory
dpkg: error processing package qgis-providers (--configure):
 installed qgis-providers package post-installation script subprocess returned error exit status 127
Setting up libqgisgrass7-3.4.5 (1:3.4.5+28bionic) ...
dpkg: dependency problems prevent configuration of qgis:
 qgis depends on qgis-providers (= 1:3.4.5+28bionic); however:
  Package qgis-providers is not configured yet.

dpkg: error processing package qgis (--configure):
 dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          Setting up libqgis-app3.4.5 (1:3.4.5+28bionic) ...
Setting up libqgis-customwidgets (1:3.4.5+28bionic) ...
dpkg: dependency problems prevent configuration of qgis-plugin-grass:
 qgis-plugin-grass depends on qgis (= 1:3.4.5+28bionic); however:
  Package qgis is not configured yet.

dpkg: error processing package qgis-plugin-grass (--configure):
 dependency problems - leaving unconfigured
Setting up qgis-provider-grass (1:3.4.5+28bionic) ...
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          Setting up python-qgis-common (1:3.4.5+28bionic) ...
Setting up python-qgis (1:3.4.5+28bionic) ...
Processing triggers for libc-bin (2.27-3ubuntu1) ...
Errors were encountered while processing:
 qgis-providers
 qgis
 qgis-plugin-grass
E: Sub-process /usr/bin/dpkg returned an error code (1)

[qgib]

Author Name: Regis Haubourg (@haubourg)

---

Hi Jürgen,
do you think this will be solved by ubuntugis next release on 22 march?

[gioman]

Not a problem nowadays.