@barbudreadmon Thank you, Nailed it!
Disabling the expired DST_Root_CA_X3.crt fixes the issue. Re-running the setup and/or a clean install, both completed successfully.
= = = = = = = = = = = = = = = = = = = = = Configuring 'retroarch' : RetroArch - frontend to the libretro emulator cores - required by all lr-* emulators = = = = = = = = = = = = = = = = = = = = = git clone --recursive --depth 1 --branch rpi "https://github.com/RetroPie/common-shaders.git" "/opt/retropie/configs/all/retroarch/shaders" Cloning into '/opt/retropie/configs/all/retroarch/shaders'... HEAD is now in branch 'rpi' at commit 'b7cdc50258908e8f1906f8fc13a2fac4a9796dc6' Downloading https://files.retropie.org.uk/binaries/retroarch-minimal-assets.tar.gz to /tmp/tmp.gjxzCRtYwm/retroarch-minimal-assets.tar.gz ... % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0 0 5263k 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0 27 5263k 27 1439k 0 0 805k 0 0:00:06 0:00:01 0:00:05 805k 100 5263k 100 5263k 0 0 2018k 0 0:00:02 0:00:02 --:--:-- 2019k = = = = = = = = = = = = = = = = = = = = = Getting sources for 'lr-snes9x' : Super Nintendo emu - Snes9x (current) port for libretro = = = = = = = = = = = = = = = = = = = = = git clone --recursive --depth 1 --branch master "https://github.com/libretro/snes9x.git" "/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x" Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x'... Submodule 'shaders/SPIRV-Cross' (https://github.com/KhronosGroup/SPIRV-Cross.git) registered for path 'shaders/SPIRV-Cross' Submodule 'shaders/glslang' (https://github.com/KhronosGroup/glslang.git) registered for path 'shaders/glslang' Submodule 'win32/DirectXMath' (https://github.com/Microsoft/DirectXMath) registered for path 'win32/DirectXMath' Submodule 'win32/libpng/src' (https://git.code.sf.net/p/libpng/code) registered for path 'win32/libpng/src' Submodule 'win32/zlib/src' (https://github.com/madler/zlib.git) registered for path 'win32/zlib/src' Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x/shaders/SPIRV-Cross'... Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x/shaders/glslang'... Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x/win32/DirectXMath'... Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x/win32/libpng/src'... Cloning into '/home/osmc/RetroPie-Setup/tmp/build/lr-snes9x/win32/zlib/src'... Submodule path 'shaders/SPIRV-Cross': checked out '1458bae62ec67ea7d12c5a13b740e23ed4bb226c' Submodule path 'shaders/glslang': checked out 'bcf6a2430e99e8fc24f9f266e99316905e6d5134' Submodule path 'win32/DirectXMath': checked out 'ffb2edbd1627e9eec75f68b4ff00e0861ad84ebe' Submodule path 'win32/libpng/src': checked out 'b78804f9a2568b270ebd30eca954ef7447ba92f7' Submodule path 'win32/zlib/src': checked out 'cacf7f1d4e3d44d871b605da3b647f07d718623f' HEAD is now in branch 'master' at commit '723521970ba1558526bea56df9deef3baac6dfc2' /home/osmc/RetroPie-Setup /home/osmc/RetroPie-Setup/tmp/build/lr-snes9x /home/osmc/RetroPie-SetupNotes: This applied to the June 2020 Update of OSMC (The last Stretch version) and as mitu pointed out, Stretch should not be considered supported.
Info about the certificate expiration can be found here
https://letsencrypt.org/docs/certificate-compatibility/
