patch 8.2.3656: Vim9: no error for an evironment variable by itself Commit: https://github.com/vim/vim/commit/65259b5c6a8ad4edaf6eeb8dbb7b50342c64d403 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Nov 23 14:52:06 2021 +0000 patch 8.2.3656: Vim9: no error for an evironment variable by itself Problem: Vim9: no error for an evironment variable by itself. Solution: Give a "without effect" error. (closes https://github.com/vim/vim/issues/9166)

--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -584,6 +584,13 @@ def Test_use_register()
   END
   CheckDefAndScriptFailure(lines, 'E1207:', 2)
   &g:showbreak = ''
+
+  lines =<< trim END
+      $SomeEnv = 'value'
+      $SomeEnv
+  END
+  CheckDefAndScriptFailure(lines, 'E1207:', 2)
+  $SomeEnv = ''
 enddef
 
 def Test_environment_use_linebreak()