- nix/wgrib2.nix: build wgrib2 3.8.0 from source with NCEPLIBS-g2c 2.3.0,
matching the Dockerfile.base build.
- flake.nix: wire wgrib2 derivation into dev shell so direnv loads it.
- DataCase: call Req.Test.set_req_test_from_context/1 in setup so
async:false tests get shared Req.Test mode, making stubs visible
to Tasks spawned by async_stream_nolink.