Make sure we source ghcup dirs in bootstrap script

Fixes #354

scripts/bootstrap/bootstrap-haskell

@@ -126,10 +126,10 @@ _eghcup() {
 	fi
     if [ -z "${BOOTSTRAP_HASKELL_VERBOSE}" ] ; then
         # shellcheck disable=SC2086
-        "${GHCUP_BIN}/ghcup" ${args} "$@"
+        "ghcup" ${args} "$@"
     else
         # shellcheck disable=SC2086
-        "${GHCUP_BIN}/ghcup" ${args} --verbose "$@"
+        "ghcup" ${args} --verbose "$@"
     fi
 }
 
@@ -228,7 +228,7 @@ posix_realpath() {
 }
 
 download_ghcup() {
-
+    if ! command -V "ghcup" >/dev/null 2>&1 ; then
         case "${plat}" in
             "linux"|"Linux")
                 case "${arch}" in
@@ -321,6 +321,7 @@ download_ghcup() {
                 edo chmod +x "${GHCUP_BIN}"/ghcup
                 ;;
         esac
+    fi
 
 	edo mkdir -p "${GHCUP_DIR}"
 
@@ -344,7 +345,9 @@ download_ghcup() {
 
 	# shellcheck disable=SC1090
     edo . "${GHCUP_DIR}"/env
-    eghcup upgrade
+    if [ -z "${BOOTSTRAP_HASKELL_NO_UPGRADE}" ] ; then
+        ghcup upgrade || yellow "Failed to upgrade ghcup, continuing anyway"
+    fi
 }
 
 # Figures out the users login shell and sets
@@ -733,13 +736,7 @@ fi
 
 edo mkdir -p "${GHCUP_BIN}"
 
-if command -V "ghcup" >/dev/null 2>&1 ; then
-    if [ -z "${BOOTSTRAP_HASKELL_NO_UPGRADE}" ] ; then
-        _eghcup upgrade || download_ghcup
-    fi
-else
 download_ghcup
-fi
 
 echo
 if [ -n "${BOOTSTRAP_HASKELL_YAML}" ] ; then (>&2 ghcup -s "${BOOTSTRAP_HASKELL_YAML}" tool-requirements) ; else (>&2 ghcup tool-requirements) ; fi