stack solver --update-config does not update the config if the resolver changes #2252
Description
I tried to use
stack solver --update-config --resolver lts-6
to change my stack.yaml from a different resolver. This works if stack solver has to apply other changes (extra-deps for example). But if the yaml requires no change but the resolver field, then stack solver says:
test -z "$STACK" || echo "resolver: lts-1.0" > stack.yaml # dummy value
test -z "$STACK" || stack solver --update-config --resolver "$STACK"
Selected resolver: lts-3.22
Using configuration file: stack.yaml
Using cabal packages:
- arbtt.cabal
No changes needed to stack.yaml