Easy install of GIMP with Flatpak.

GIMP is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, converting between different image formats, and more specialized tasks. GIMP is released under GPLv3+ licenses and is available for Linux, macOS, and Microsoft Windows, see Wikipedia.
Flatpak is a software utility for software deployment and package management for Linux. It is advertised as offering a sandbox environment in which users can run application software in isolation from the rest of the system. see Wikipedia.
Flatpak builds available in i386, x86-64, ARM and AArch64.

[root@desk mythcat]# dnf install flatpak.x86_64 
Last metadata expiration check: 0:27:27 ago on Fri 01 Nov 2019 11:27:47 PM EET.
Dependencies resolved.
...
Installed:
  flatpak-1.4.3-1.fc30.x86_64                                                   
  p11-kit-server-0.23.16.1-1.fc30.x86_64                                        
  xdg-desktop-portal-1.4.2-1.fc30.x86_64                                        
  xdg-desktop-portal-gtk-1.4.0-1.fc30.x86_64                                    
  flatpak-selinux-1.4.3-1.fc30.x86_64                                           
  flatpak-session-helper-1.4.3-1.fc30.x86_64                                    
  ostree-libs-2019.4-3.fc30.x86_64                                              

Complete!

The install and run of last GIMP software is easy, see commands:

[mythcat@desk ~]$ flatpak install https://flathub.org/repo/appstream/org.gimp.GIMP.flatpakref

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so applications installed by 
Flatpak may not appear on your desktop until the session is restarted.

Required runtime for org.gimp.GIMP/x86_64/stable (runtime/org.gnome.Platform/x86_64/3.32) found in remote
 flathub
Do you want to install it? [Y/n]: Y       

org.gimp.GIMP permissions:
    ipc                   network        x11       file access [1]
    dbus access [2]       tags [3]

    [1] /tmp, host, xdg-config/GIMP, xdg-config/gtk-3.0
    [2] org.freedesktop.FileManager1, org.gtk.vfs, org.gtk.vfs.*
    [3] stable
        ID                                    Arch   Branch Remote  Download
        ID                                    Arch   Branch Remote  Download
 1. [✓] org.gnome.Platform                    x86_64 3.32   flathub 360.0 MB / 374.0 MB
 2. [✓] org.gnome.Platform.Locale             x86_64 3.32   flathub  17.4 kB / 320.0 MB
 3. [✓] org.freedesktop.Platform.VAAPI.Intel  x86_64 18.08  flathub   1.8 MB / 1.8 MB
 4. [✓] org.freedesktop.Platform.html5-codecs x86_64 18.08  flathub   3.2 MB / 3.3 MB
 5. [✓] org.gimp.GIMP                         x86_64 stable flathub 106.5 MB / 108.9 MB

Installation complete.
[mythcat@desk ~]$ flatpak update

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the session is restarted.

Looking for updates…
Nothing to do.
[mythcat@desk ~]$ flatpak run org.gimp.GIMP//stable

Note that the directories 

'/var/lib/flatpak/exports/share'
'/home/mythcat/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so
applications installed by Flatpak may not appear on your desktop until the session is restarted.

GIMP-Error: Skipping '/home/mythcat/.var/app/org.gimp.GIMP/config/GIMP/2.10/pluginrc
wrong GIMP protocol version.
...