these 2 derivations will be built:
  /nix/store/7br2wc7cmdzkm2iqbgqpkqrni5gm84x9-sci-fi_hallway_demo.zip.drv
  /nix/store/4vkzpd3crvpl3jcvnmql8jzy4b6y94js-ue4demos-scifi_hallway_demo.drv
building '/nix/store/lkg6csid5asbwsixwh42vdi2rbc7ij0l-sci-fi_hallway_demo.zip.drv'
sci-fi_hallway_demo.zip> 
sci-fi_hallway_demo.zip> trying https://ludios.org/mirror/ue4demos/sci-fi_hallway_demo.zip
sci-fi_hallway_demo.zip>   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
sci-fi_hallway_demo.zip>                                  Dload  Upload   Total   Spent    Left  Speed
sci-fi_hallway_demo.zip> 100  424M  100  424M    0     0  16.5M      0  0:00:25  0:00:25 --:--:-- 14.2M
building '/nix/store/4vkzpd3crvpl3jcvnmql8jzy4b6y94js-ue4demos-scifi_hallway_demo.drv'
ue4demos-scifi_hallway_demo> Archive:  /nix/store/5dmqy81z59f784zm07hdrkd15ag6sisp-sci-fi_hallway_demo.zip
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/Engine/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/Engine/Binaries/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/SciFiHallway  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicudata.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicui18n.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicuio.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicule.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libiculx.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicutu.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libicuuc.so  
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/Engine/Binaries/Linux/libopenal.so.1  
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/SciFiHallway/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/SciFiHallway/Content/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/SciFiHallway/Content/Paks/
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/SciFiHallway/Content/Paks/SciFiHallway-LinuxNoEditor.pak  
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/SciFiHallway/Saved/
ue4demos-scifi_hallway_demo>    creating: Sci-Fi Hallway Demo/SciFiHallway/Saved/Config/
ue4demos-scifi_hallway_demo>   inflating: Sci-Fi Hallway Demo/SciFiHallway/Saved/Config/controller.vdf  
ue4demos-scifi_hallway_demo> Sci-Fi Hallway Demo

upload niks3: ok