As someone who has the requirement for Citrix at work, the fact Solus wouldn't work with it kept me switching and evaluating other distros. As I finally was able to get this to work yesterday, I wanted to share this for anyone who this may be a stumbling block for.
1) I downloaded the tar for the last version of Receiver before the Workspace App, which I believe is 13.10
2) Extracted it and ran the ./setupwfc, just follow the prompts.
3) In your home directory you will now have an ICAClient folder structure. Citrix still won't work.
4) I'd read from others about the trusted root certificate issue in Linux; there is a store for Citrix Receiver, in Solus it's under the above mentioned ICAClient/linux64/keystore/cacerts directory. Older posts I'd read for other distros talked about copying the certs from Mozilla. I ended up copying them from the OpenSUSE VM I'd been running on Solus as they were exposed as files from Mozilla there into the cacerts directory for Citix I just mentioned above. If anyone can improve on this post by copying them from Solus or a trusted download location, that would be great.
5) After copying the certs, you need to run the ctx_rehash command as in this Citrix article:
Just remember that the path to the utility is different in Solus, it's not under /opt/Citrix, but under your home directory/ICAClient/linux64/util/
6) Now, sadly, Citrix still doesn't work. This is where my troubleshooting ended on previous attempts. Yesterday, for whatever reason, I went to the command line and ran .wfica rather than just logging into our Citrix site and having nothing happen. I received the following message:
/ICAClient/linuxx64 $ ./wfica
./wfica: error while loading shared libraries: libidn.so.11: cannot open shared object file: No such file or directory
libidn package was installed and used by other apps, so I was confused as to why it didn't work. I googled "libidn.so.11" and found the following post regarding the Linux Receiver on Slackware:
Looking in my /usr/lib64/ the version of the file I have (as of March 2nd 2019 when I'm posting this) is libidn.so.12, so I created a symbolic link with the following command: sudo ln -sf /usr/lib64/libidn.so.12 /usr/lib64/libidn.so.11
Went back and logged into our Citrix site, and everything works from Solus. I would expect that if libidn get's upgraded you will need to create a new symbolic link. I hope this helps someone, it would have been nice if the app and all the dependencies and certs were in place from the start. If anyone can improve or simplify anything I've posted, that would be great.