OK, was able to ascertain a few more things as recommended:

Did this:
Ended up with:
For the hell of it, did a "du -h /install_from/slackware64/" and got this:
Did a "du -s /install_from/slackware64/" and got this:
I hope this is a clue? It is not to me but hopefully is to others.

I get the same results, so I assume that the packages being included the problem has another cause.

It could help to try again and tell us what exact steps you took and the exact commands you typed. You could also witch to the fourth terminal that logs the messages (Alt+F4) to see the error messages that could be displayed, just before then after the INSTALL step.

But there is another way to install the packages, that is to manually run the script installpkg provided in the installer. To do that, start the installer and follow the steps up to and including TARGET. Choose to format the new root partition (/dev/sdc1 if that has not changed) with an ext4 file system.

As soon as you see the dialog's title SOURCE MEDIA SELECTION, switch to another terminal hitting Alt+F2

Then type:You should see you target partition (that will become / when your new system will be running) mounted on /mnt.

Next, to install all packages just do this:This will of course take a while.

When, it's finished just go back to the first terminal (Alt+F1) and choose Cancel: this will display the main menu again.

Then choose CONFIGURE to proceed to the configuration of your new system.

If you want to skip e.g. the kdei series, instead ofyou could write:Just take care that "a" be the first series so that the package aaa_base be the first installed.

It maybe a bad download of the iso file. Have you done a md5sum check on it? A corrupted iso file will cause things to go wrong.

@colorpurple21859: good idea. I checked. The ISO's checksum is good.

@Didier Spaier:

The exact sequence.

One. Stick boot-from USB stick into machine. Reboot machine. Succesfully boot off of USB. Skip keymap choice part. Log in as root. Stick second USB stick in. This is the install-to USB. It's 16 gig, so large enough to fit Slackware. The reason I wait to insert it is sometimes the machine will fail to boot (two usb's confuses it?) and also to keep straight which one is sdb and which is sdc. For whatever reason, regardless of how I boot, the machine's internal HD is always sda.
I get a message about sdb being mounted read-only. Logical, since it is an ISO 9-whatever cd/dvd file system. sdc has been previously partitioned, all as one primary partition.

I then run setup. I skip the swap part. I've got enough RAM that I don't need swap. The target screen of setup is where sdc is formatted. Since it is a USB stick, I chose a non-journaling file system: ext2.

I then chose the source, by the method of a path to a directory, /install_from.

I am then presented with the first choice on the packages, which I leave at the default of everything but the extra language support for KDE. At the next screen, I tell it to install Full, without prompting.

After a half second, it claims to be finished. As usual, nothing but a var directory.

Consulting the alt-f4 error console before and after shows *no error messages* during that last part. Oh. Unexpected.

NEXT (your manual install idea using installpkg)

I tried the manual workaround. That began to install packages. Fascinating. After about an hour of waiting I went to the alt-F2 console and looked around. I could see clear evidence that packages were being installed (many directories off of /mnt). Good. I saw no fstab. Bad. Taking this last as a warning sign, I aborted the process.

NEXT: something different.

I ran a virtual machine. In this, Setup was able to auto-detect the emulated CD-ROM. OK: fails in reality, works in virtual. My real machine is being stupid.

Reset the virtual machine. This time I used the technique of mounting the directory and installing from that. Guess what, the *same* problem happened as in the real install! After a half second, the installer claimed that all was done but when I checked, I saw nothing but a var directory. Fascinating.

Tentative conclusion: there are actually two seperate problems here.

(1) with regard to usb-as-cdrom, my machine is stupid.

(2) the install-from-path problem can be replicated in physical *and* virtual machine. This means that either there is a real bug in the Slackware installer's install-from-path function *or* I am doing something wrong (but cannot see what).

First of all, we all would have saved *a lot of time* if you had told us in your first post that you tried to install on an USB stick.

I tried to reproduce your steps and got the same result.
So yes there *seems* to be a bug in the installer when installing on an USB stick instead of a hard disk's partition: I chose "Install from a Slackware USB stick" and it proposed /dev/sdd2/ (that didn't exist) instead of /dev/sdd1 (expected), with the variable SeTsource set to /dev/null. Not good. I tried other sources and didn't succeed either.

However the method I proposed you in my previous post does work.

EDIT: well, I am not sure. I have a lot of files with size 0 in the stick, so something did go wrong

Wrong. As I told you, the file /mnt/etc/fstab is written *after all packages are installed* in the CONFIGURE step, so so you should have waited till the end of installation through installpkg (you know it has finished when you get back the prompt) and proceeded to CONFIGURE as instructed.

But as I am not sure that really works, I advise to install Slackware on an hard disk's partition, not on an USB stick

However if you persist and succeed with the USB stick I suggest that you don't install lilo (that would be complicated because you would need to chroot to /mnt before rebooting and modify /etc/fstab to name your root partition by UUID. Instead, I suggest that your add an entry for Slackware to your current boot menu (still naming your root Slackware partition by UUID as its name can change, which is normal).

I created a new partition table and formated the usb to ext2 using gparted in ubuntu because the installer wasn't even seeing the usb beforehand, it had a fat32 partition on it at the beginning. Then installing using the ops method in setup worked for me. the issue I have is it hangs when trying to reboot, won't reboot have to do a hard shutdown with power switch.

I'll try to find later out if there is really a bug and if it that happens only if the installer is on an USB stick as the target of nstalletion, or also if it is on an optical media.

I was able to install to a usb that had an ext2 formatted partition, from a usb with the iso on it using DD. however before I reformated the usb-installto using gparted, fdisk on the usb-installfrom saw the usb-installto but in setup did not have the usb-installto as one of the choices during target selection until after I formatted it using gparted.

Thank you for the replies, and especially for being able to replicate some of the problem. At this point I find myself unclear if what I was intending to do is actually possible. I had thought one would just treat a USB as another hard drive but apparently not? I wonder if an external hard drive fail in a similar way. That would take me a while to set up (have to move the data off to other media). The USB was intended as a test, before doing the real install on the HD. At this point, since installing from a USB is flaky on my machine, it is unsure if any install is actually possible?

I realize that going through the slackare install scripts/program(s) used by Setup should enable me to figure out to do a completely low-level manual install, gentoo-style (well, aside from the compiling) but I expect that any discussion of that would be off topic and would have to be on a new thread.

Not at all. That works. See this thread.