Test bootstrap-haskell wrt #72

.gitlab/script/ghcup_bootstrap.sh

+#!/bin/sh
+
+set -eux
+
+. "$( cd "$(dirname "$0")" ; pwd -P )/../ghcup_env"
+
+mkdir -p "$CI_PROJECT_DIR"/.local/bin
+
+ecabal() {
+	cabal --store-dir="$(pwd)"/.store "$@"
+}
+
+eghcup() {
+	ghcup -v -c -s file://$(pwd)/ghcup-${JSON_VERSION}.yaml "$@"
+}
+
+git describe --always
+
+### build
+
+ecabal update
+
+export BOOTSTRAP_HASKELL_NONINTERACTIVE=yes
+export BOOTSTRAP_HASKELL_GHC_VERSION=$GHC_VERSION
+export BOOTSTRAP_HASKELL_CABAL_VERSION=$CABAL_VERSION
+
+./bootstrap-haskell
+