foreman: allow using substitutes by default

Dependencies

• [2] PGSWHMH6 Run `hydra-dev-server`
• [3] 2POTELFE Add hydra-notify to devshell
• [4] KPWMZFHZ Add runHydra shell
• [5] LEQWZ3IJ Use custom ports for postgres/hydra

Change contents

• edit in foreman/start-evaluator.sh at line 6
  [4.893]→[4.195:224](∅→∅)
  − touch .hydra-data/hydra.conf
• replacement in foreman/start-hydra.sh at line 11
  [4.1165]→[4.394:423](∅→∅)
  − touch .hydra-data/hydra.conf
  [4.1165]

  [2.0]
  + if [ ! -f ./.hydra-data/hydra.conf ]; then

  + echo "Creating a default hydra.conf"

  + cat << EOF > .hydra-data/hydra.conf

  + # test-time instances likely don't want to bootstrap nixpkgs from scratch

  + use-substitutes = true

  + EOF

  + fi
• edit in foreman/start-notify.sh at line 6
  [3.137]→[3.137:166](∅→∅)
  − touch .hydra-data/hydra.conf
• edit in foreman/start-queue-runner.sh at line 6
  [4.1486]→[4.674:703](∅→∅)
  − touch .hydra-data/hydra.conf