This adds a devShell which unlike runHydra doesn't start hydra
automatically and doesn't receive hydra as build input. It is better
suited for interactive development cycles:
$ nix-shell -A devShell
$ ./bootstrap
$ configurePhase
$ make
$ # hack hack hack
$ foreman start
# test test test
<C-c>
$ # hack hack hack
RXJZO7EV5JTZHFIVF7Y3B5A3NIGOPOQQHBWMVFSJFLBDS6MJL6HAC devShell = pkgs.hydra.overrideAttrs (old: {buildInputs = old.buildInputs ++ [ pkgs.foreman pkgs.netcat ];shellHook = old.shellHook + ''export HYDRA_HOME="src/"mkdir -p .hydra-dataexport HYDRA_DATA="$(pwd)/.hydra-data"export HYDRA_DBI='dbi:Pg:dbname=hydra;host=localhost;''';});