dnf distro-sync && dnf install steam

yum-config-manager --enable updates-testing && dnf update && dnf install steam

$ sudo dnf distro-sync && dnf install steam
Ошибка: Failed to synchronize cache for repo 'updates' from 'https://mirrors.fedoraproject.org/metalink?repo=updates-released-f21&arch=x86_64': Cannot prepare internal mirrorlist: Curl error: SSL connect error for https://mirrors.fedoraproject.org/metalink?repo=updates-released-f21&arch=x86_64 [TCP connection reset by peer]

 [1ns@f21 ~]$ steam 
Running Steam on fedora 21 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(0_client)
/home/1ns/.local/share/Steam/steam.sh: line 730:  6305 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"