Some time ago I wrote about Citrix Receiver In Mozilla Firefox (64-bit) In Slackware64-current. Citrix Receiver has been replaced by Citrix WorkSpace. These are the steps to install it in Slackware64-current.
1) Repackage and install libmanette (SlackBuild: https://github.com/conraid/SlackBuilds/tree/master/libmanette and package: https://ftp.acc.umu.se/pub/GNOME/sources/libmanette/) and webkit2gtk (SlackBuild: http://cgit.ponce.cc/slackbuilds/tree/libraries/webkit2gtk and package: https://www.webkitgtk.org/releases/)
2) Download the "Tarball Packages" Citrix WorkSpace app for Linux (x86_64) from https://www.citrix.com/downloads/workspace-app/linux/workspace-app-for-linux-latest.html
3) Untar the package
4) Open a terminal, su, enter root password
5) Run ./setupwfc and accept all defaults for installation
6) cd /opt/Citrix/ICAClient
7) Run ./selfservice or open Citrix WorkSpace app from KDE menu
8) Check https://www.citrix.com/content/dam/citrix/en_us/documents/downloads/citrix-receiver/linux-oem-guide-13-1.pdf for information on mapping drives (Hint: Search for "DrivePathA...Z" on page 72 of 104 and read on ~/.ICAClient/wfclient.ini file)
Regards,
F. Bobbio C.