Hello Guix! LINPHONE WORKS! \o/
Now we have a working client. It is a Legacy GTK version (linphone/liblinphone). I am still working on Qt version (linphoneqt/linphone-desktop). Please test the client and let me know if there is any issue. The latest revision patch is "13-add-linphone-v3" at https://issues.guix.gnu.org/issue/40264. Thank you! Regards, RG.