Dynamic rules lose their value in between builders (and also in between analysis phase and calling a builder) in Spoofax.

Steps to reproduce:

1) create new Spoofax language project

2) add builders:

rules

  debug-set-index:
    (selected, position, ast, path, project-path) -> None()
    with
      rules(Index := ["foo", "bar"])
      
  debug-show-index:
    (selected, position, ast, path, project-path) -> (filename, result)
    with
      filename := <guarantee-extension(|"index.aterm")> path;
      result   := <Index;debug(!"stored index ") <+ !"Index is emtpy"> //TODO: why is the index empty?

menus
  
  menu: "Dynamic Rules" (openeditor)
    
    action: "debug-set-index"  = debug-set-index
    action: "debug-show-index" = debug-show-index

3) create a new language file, call first builder, call second builder.

Expected output: file with ["foo", "bar"]

Actual output: file with Index is emtpy

Spoofax version:

Eclipse: org.eclipse.platform.ide 4.6.0.I20160606-1100
Spoofax: org.metaborg.spoofax.eclipse 2.1.0.20160919-225254-master
System: Mac OS X x86_64 10.11.6

Submitted by Daco Harkes on 26 September 2016 at 10:42

Possible work around: store in file.

Actually not: attachments get lost.

It should reuse the dynamic rules between invocations on the same language and project, so this is probably a bug. Unfortunately, the code that maintains Stratego dynamic rules is very hacky and I do not know how to do this.