.:Slackel - Hellenic Linux Distribution::.

There is a problem after today's system update, at least on the 64-bit Openbox version (I didn't update my Slackel 32-bit installation yet, until the problem is solved). Specifically, I updated aaa-elflibs first (separately, as usual), then proceeded by updating the rest of the system, which seemed to work fine. But when I tried to reboot and relogin I see this: This makes the system unusable at the moment. Apparently, there is a problem with libpam, and the solution is probably to boot from USB, mount the system and fix the libpam issue somehow. But before proceeding with risky trial-and-error, I thought it is wise to ask here first.

From slackware changelog "Greetings! After three months in /testing, the PAM merge into the main tree
is now complete. When updating, be sure to install the new pam, cracklib, and
libpwquality packages or you may find yourself locked out of your machine."
So download pam, cracklib, libpwquality and boot with usb to install these packages.
Mount the partition where slackel exists and use
sudo installpkg --root partition_where__slackel_installed package_name.txz
Then reboot.
The problem happened because of new libpwquality (password quality checking library) package. If you have installed it then pam and cracklib will also be installed as deps.
It is good to always check slackware Changelog for new packages that added in repos, before proceed to update.
There is also openldap package added and openldap-client removed.

Problem solved, as djemos suggested. It seems the new pam package was added since 18 May 2020, and I didn't update my system since then - until today. I was aware of Slackware-current changelog, I should look there first. I am sorry for that.

Thank you Dimitri for providing (once again) quick and very helpful information.

This is one of the problems appeared in slackware current and it is not easy to solve it, for not experienced slackware/slackel users.
libpwquality it is not a dep for any package.
Pam and cracklib are deps for libpwquality.
Since shadow will be upgraded and pam is a dep for it, i also added there libpwquality as a dep even it is not.
So cracklib will allso be downloaded and installed.
I hope problem is solved.