I tried a clean disk install with slackware64-current-20220802 from a usb key. Not good results.

1. When I tried a usb boot on the slackware64-current iso (UEFI or legacy) I got the standard lilo snafu - the 'L' followed by rows of '99 99…' I tried CSM - same result. In fact nothing would boot
2. I made a 2nd usb with the slackware64-15.0-install.iso. That booted fine, I started an install, and when it asked for a disk with the slackware packages, I pulled out the 15.0 install & inserted the slackware64-current iso. Installed fine, set up elilo, but elilo wouldn't boot.

When I tried to boot with elilo, I got three initial lines only, then the screen went black, then the bios boot repeated. When I booted slackware64-15.0, I get the three lines, but on the fourth is a '—' while kernel & initrd load, then the kernel messages start.

I spent a while double checking, but this is repeatable. So I reinstalled slackware64-15.0, and am posting from it now.

If I made an obvious goof, keep me humble(!). If there's a quick fix or workaround, let me know.

Does the Aug. 2 iso use 5.19? There's a problem with the efi stub in it, and people were having problems booting from it directly. Might want to try one with 5.18.16, instead.

When I saw a fast reply, I thought I was being kept humble
Yes August 2 does use 5.19.0. That's a probable cause for fault 2. Thanks for that. It's always inadvisable to get any kernel with '0' as the last number

So I can feel ok about myself. I'm going to come up for air before doing any more installs. It seemed I was trying to install where the Bermuda Triangle intersected with the Twilight zone. Murphy's law had a field day.

That might explain both faults in my post. What it doesn't explain is why I saw the classic lilo snafu and only one partition, unless you're not supposed to install from Current?

Legacy *should* work, though. My desktop (UEFI) had problems with 5.19 before the elilo patch. My laptop (LILO, legacy BIOS mode) had no problems. Both are on current.

However, from my experience the LILO has its own share of issues on CSM mode of modern UEFI motherboards.

Let's say that OP had a really bad inspiration on trying to install exactly that particular day ISO. Murphy's law at work, as himself said.

A thing I didn't make clear is that there only seemed to be one partition in the August 2nd iso, whereas slackware64-15.0 had two. As an example of my weekend, I tried to loop mount the current iso to take a look. It is puking with the error "Unknown filesystem 'iso9660' although I tried it with & without the '-t' option. The laptop mounted it, of course. Same kernel & modules on both .

The usb keys: Slackware-15.0 has 2 partitions under fdisk, but ~current has only one.

Where are you getting your ISO? Slackware does not offer an ISO for -current so perhaps you made one yourself?
I downloaded one from https://us.slackware.nl/slackware/sl...4-current-iso/ and that ISO has two partitions:

ftp://ftp.heanet.ie/pub/ftp.slackwar...2_Aug_2022.iso
Or, in text with spaces so it won't fold:
ftp.heanet.ie/pub/ftp.slackware.com /pub/slackware/slackware-iso /slackware64-current-iso/ slackware64-current-02_Aug_2022.iso

Apparently the script to generate that ISO is here: http://www.slackware.no/makeSlackISOs.sh
I looked at the script, it has a 2015 timestamp and it does not add UEFI support. Nor does it make a hybrid ISO, so copying it to a USB stick using 'dd' or 'cp' will result in an unbootable USB stick.

Ha! Thanks for that. That was me being dutiful and staying on my local mirror…

But I don't need another iso. I mirrored the directories, I have my clean install of 15.0, I have the (slightly modified) directories, so I can just do the 'upgradepkg' trick on that, clean up the/boot/efi stuff to reflect the new reality, and then reboot.

I will probably do that - but not yet . I want to come up for air first. What I'd like to know is how did you track heanet's iso-making script?

Not so hard to find out. It's mentioned in the README.TXT in the same directory as where you downloaded the ISO: https://ftp.heanet.ie/pub/ftp.slackw...iso/README.TXT .

Note that your URL is incorrect if you want to use https instead of the deprecated ftp protocol, there is only a 'slackware-current-iso' directory, no 'slackware64-current-iso' directory.

Thanks. I remember my way around in heanet, and just run 'ls' near the end because names can change there. They used to have a directory 'mirrors/' beside pub/, so I would use 'mirrors/slackware' instead of 'pub/ftp.slackware.com'. But that vanished one day. They also had a directory split in the current isos, IIRC, but that's gone too. Speed has improved, however. They must have a bigger pipe, or everyone got fed up with them and cleared off.