How long should the following build normaly take, when the correct "IOHK binary cache" is set at "nix.conf"?
nix-build -A plutus-playground.server
For me it took roughly 2-4 hours on virtual box but it really depends on what environment your setting it up in. For example a virtual box will take much longer than a computer running on Linux or a wsl instance. Overall expect to wait 30 min - 4h.
For me it's as follows:
nix-build -A plutus-playground.server
-> 262s
nix-build -A plutus-playground.client
-> 25s
nix-shell
-> 1715s
This is after properly setting all the IOHK caches correctly.