hp-setup fails on Ubuntu and Fedora due to expecting sane libraries in wrong directories

[valent]

On Fedora 28, 29 and 30 I see this issue - driver is installed but I can't finish adding printer if it has to load hp-plugin module (models with scanner). Printers without scanner and no need for hp-plugin install without problem.

I'm using latest HPLIP 3.19.8 but also older HPLIP 3.19.1 has same issue.

Here is the error that shows up when hp-setup tries to install gpg keys:

sudo /usr/bin/gpg --homedir /root/.hplip/.gnupg --no-permission-warning --keyserver pgp.mit.edu --recv-keys 0x4ABA2F66DBD5A95894910E0673D770CDA59047B9
gpg: requesting key A59047B9 from hkp server pgp.mit.edu

gpgkeys: key 4ABA2F66DBD5A95894910E0673D770CDA59047B9 can't be retrieved
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
gpg: keyserver communications error: keyserver helper general error
gpg: keyserver communications error: unknown pubkey algorithm
gpg: keyserver receive failed: unknown pubkey algorithm

I also see error when trying to download hp-plugin directly from the web:

Checking for network connection...
Downloading plug-in from:
Plugin is not accessible. Trying to download it from fallback location: [https://developers.hp.com/sites/default/files/hplip-3.19.8-plugin.run]
Receiving digital keys: /usr/bin/gpg --homedir /home/user/.hplip/.gnupg --no-permission-warning --keyserver pgp.mit.edu --recv-keys 0x4ABA2F66DBD5A95894910E0673D770CDA59047B9
Creating directory plugin_tmp
Verifying archive integrity... All good.
Uncompressing HPLIP 3.19.8 Plugin Self Extracting Archive..............................................................

After I manually download hp-plugin and load it via hp-setup gui then it installs without errors, but it still fails after that to install the printer which is really strange.

So I get same behaviour when hp-plugin fails to install and when it is installed correctly.

I have Selinux disabled.

[valent (valent-turkovic)]

Here is also full hp-setup log, it shows lots of missing libraries because on Fedora and Ubuntu they are located in different directories and hp-setup is not flexible enought to recognise this and work around it.

then, made the symlinks:

/usr/lib/i386-linux-gnu/sane -> /usr/lib/sane
/usr/lib/x86_64-linux-gnu -> /usr/lib64/x86_64-linux-gnu
/usr/lib64/x86_64-linux-gnu/sane -> /usr/lib64/sane

and hp-setup finally works and adds printer!

Solved thanks to @zaskar_84 from LQ forums:
https://www.linuxquestions.org/questions/showthread.php?p=6045970

[valent (valent-turkovic)]

This is how hp-setup would fail, even after reporting hp-plugin has installed without errors. All due to hp-setup looking for sane libraries at wrong (non-existing) locations.

[shivani mandora (shivani1708)]

Hi,

Can you please install plugin using below command:

$sh hplip-3.19.8.plugin.run

If plugins are installed properly, you will be able to configure scanners without any error.
If you still face any issue after this, please let me know.

[valent (valent-turkovic)]

@shivani now that I have configured symlinks hp-setup works, but on a clean system and as well on mine with additional symlinks I can install hp-plugin without probblem.
But still each time I start hp-setup it asks me to install hp-plugin again and again.

Only solution that works was to setup symlinks as mentiones in comment #2.