test(GETARGS): set NEWROOT and PREFIX for dracut-lib.sh

Set `NEWROOT` to an existing directory to make sourcing `dracut-lib.sh`
work with `set -u`. Also set `PREFIX` to avoid creating `/run/initramfs`
which requires root permission.

diff --git a/test/TEST-80-GETARG/test.sh b/test/TEST-80-GETARG/test.sh
index aed1cdf92b7a6bf003bfed288e0f70c96e21992e..0bc4709e99deac0486d41478413268783dce48b3 100755 (executable)
--- a/test/TEST-80-GETARG/test.sh
+++ b/test/TEST-80-GETARG/test.sh
@@ -86,6 +86,10 @@ test_run() {
         [[ $val ]] && ret=$((ret + 1))
 
         export PATH=".:$PATH"
+        # shellcheck disable=SC2034  # NEWROOT defined for dracut-lib.sh, set by base/init.sh
+        NEWROOT=$(mktemp --directory -p "$TESTDIR" newroot.XXXXXXXXXX)
+        # shellcheck disable=SC2034  # PREFIX defined for dracut-lib.sh to avoid creating /run/initramfs
+        PREFIX=/nonexistent
 
         . dracut-dev-lib.sh
         . dracut-lib.sh