If you’re running an x86_64 version of Slackware, you’ll need to preface the above command like this:

# ARCH=x86_64 ./pysolfc.SlackBuild

No, you can do it but not need. pysolfc.SlackBuild (and others on slackbuilds.org) has some code for this:

if [ -z "$ARCH" ]; then
  case "$( uname -m )" in
    i?86) ARCH=i486 ;;
    arm*) ARCH=arm ;;
       *) ARCH=$( uname -m ) ;;
  esac
fi

“$( uname -m )” returns “x86_64” on Slackware64, so ARCH gets right value by default.
— bormant

You are correct, bormant. I remember when Slackware first came out with a 64 bit version and we had to do this for all the SlackBuilds initially. This tutorial was originally written a few years back. That's why that method is still in there. It does no harm, though. I may remove it, eventually. Thank you! ~vtel

I think you should remove the comment because the ARCH detection block has been part of Slackware scripts and those in 3rd party repositories for quite a while.
What you could do is make a suggestion that the user checks the script for the presence of an ARCH block if she wants to be absolutely sure of the outcome.
— Eric Hameleers 2012/08/26 12:21

I just removed it completely (on the original source, also). The fact is that a user would probably have a hard time finding an old SlackBuild script without the ARCH detection at this point. Thanks, bormant and Eric. — V. T. Eric Layton 2012/08/28 10:39

Looking through the HOWTOs I found this article again, and the title “Let's build a SlackBuild” put me on the wrong foot. I thought it was an article about “how to write a SlackBuild script”, where in reality this article is about “creating a package using a script from the SlackBuilds.org site”. Perhaps you can consider changing the title?
— Eric Hameleers 2012/09/21 13:59

Being new to Slackware, I interpreted it as “Let's write as Slackbuild” too. It is a rather confusing title. — Mario St-Gelais 2012/09/21 14:47

Bad title. I agree. Fixed now. — V. T. Eric Layton 2012/09/21 18:24