Create ghci.cabal.sh

hadrian/ghci.cabal.sh

+#!/usr/bin/env sh
+
+set -e
+
+GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build.cabal.sh" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci "$@")"
+ghci $GHC_FLAGS "$@" -fno-code -fwrite-interface -hidir=.hadrian_ghci/interface -O0 ghc/Main.hs +RTS -A128m

hadrian/ghci.sh

-#!/usr/bin/env sh
+#!/usr/bin/env bash
 
-set -e
-
-GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build.cabal.sh" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci "$@")"
-ghci $GHC_FLAGS "$@" -fno-code -fwrite-interface -hidir=.hadrian_ghci/interface -O0 ghc/Main.hs +RTS -A128m
+# By default on Linux/MacOS we build Hadrian using Cabal
+(. "hadrian/ghci.cabal.sh" "$@")