@igrep stack.yamlのresolverでしょうかね？いまいちわかりません...参考までにstack.yamlのコードです
# This file was automatically generated by 'stack init'
#
# Some commonly used options have been documented as comments in this file.
# For advanced use and comprehensive documentation of the format, please see:
#
# Resolver to choose a 'specific' stackage snapshot or a compiler version.
# A snapshot resolver dictates the compiler version and the set of packages
# to be used for project dependencies. For example:
# resolver: lts-17.14
# resolver: nightly-2015-09-21
# allow-newer: true
# system-ghc: true
#
# The location of a snapshot can be provided as a file or url. Stack assumes
# a snapshot provided as a file might change, whereas a url resource does not.
#
# resolver: ./custom-snapshot.yaml
# resolver:
resolver:
url:
# resolver: ghc-8.10.5
# User packages to be built.
# Various formats can be used as shown in the example below.
#
# packages:
# - some-directory
# -
# subdirs:
# - auto-update
# - wai
# packages:
# - .
# Dependency packages to be pulled from upstream that are not in the resolver.
# These entries can reference officially published versions as well as
# forks / in-progress versions pinned to a git hash. For example:
#
# - acme-missiles-0.3
# - git:
# commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
#
# extra-deps:
# Override default flag values for local packages and extra-deps
# flags: {}
# Extra package databases containing global packages
# extra-package-dbs: []
# Control whether we use the GHC we find on the path
# system-ghc: true
#
# Require a specific version of stack, using version ranges
# require-stack-version: -any # Default
# require-stack-version: ">=2.7"
#
# Override the architecture used by stack, especially useful on Windows
# arch: i386
# arch: x86_64
#
# Extra directories used by stack for building
# extra-include-dirs: [/path/to/dir]
# extra-lib-dirs: [/path/to/dir]
#
# Allow a newer minor version of GHC than the snapshot specifies
# compiler-check: newer-minor