You can use Stack and the Stackage snapshots with GHC 7.10.3 right now!
By default (since v0.1.4), Stack insists that the minor version of GHC matches the version that was used to build the Stackage snapshot. This means that using the current LTS 3.x and nightly snapshots will require GHC 7.10.2, even if GHC 7.10.3 is installed (as this is the safest option for reproducability). However, this behaviour can be changed using the compiler-check option. Just add the following to your project's
stack.yaml, or to
~/.stack/config.yaml (if you prefer it to apply to all projects):
Then, install GHC 7.10.3:
$ stack setup 7.10.3
stack build and related subcommands will use GHC 7.10.3.
Related: as soon as possible (i.e. the snapshot builds successfully and passes tests), new Stackage nightly snapshots will require GHC 7.10.3. If possible, newer LTS 3.x snapshots will also be moved to GHC 7.10.3 (see fpco/stackage#1029).