filepath.matches("%/main.rs")

  /**
   * Returns a relevant locatable for debugging, configurable by line number.
   */
  private Locatable getRelevantLocatable(int startline) {
    exists(string filepath, int sline, int startcolumn, int endline, int endcolumn |
      result.getLocation().hasLocationInfo(filepath, sline, startcolumn, endline, endcolumn) and
      filepath.matches("%/main.rs") and
      sline = startline
    )
  }

  /** Convenience: default line number for debugging. */
  private int defaultDebugStartLine() { result = 167 }

  /** Overload for backward compatibility: uses default line number. */
  private Locatable getRelevantLocatable() { result = getRelevantLocatable(defaultDebugStartLine()) }

  predicate debugUnqualifiedPathLookup(
    RelevantPath p, string name, Namespace ns, ItemNode encl, string path
  ) {
    p = getRelevantLocatable(defaultDebugStartLine()) and
    unqualifiedPathLookup(encl, name, ns, p) and
    path = p.toStringDebug()
  }

  ItemNode debugResolvePath(RelevantPath path) {
    path = getRelevantLocatable(defaultDebugStartLine()) and
    result = resolvePath(path)
  }

  predicate debugUseImportEdge(Use use, string name, ItemNode item, SuccessorKind kind) {
    use = getRelevantLocatable(defaultDebugStartLine()) and
    useImportEdge(use, name, item, kind)
  }

  ItemNode debugGetASuccessor(ItemNode i, string name, SuccessorKind kind) {
    i = getRelevantLocatable(defaultDebugStartLine()) and
    result = i.getASuccessor(name, kind)
  }

  predicate debugFileImportEdge(Module mod, string name, ItemNode item, SuccessorKind kind) {
    mod = getRelevantLocatable(defaultDebugStartLine()) and
    fileImportEdge(mod, name, item, kind)
  }

  predicate debugFileImport(Module m, SourceFile f) {
    m = getRelevantLocatable(defaultDebugStartLine()) and
    fileImport(m, f)
  }

  predicate debugPreludeEdge(SourceFile f, string name, ItemNode i) {
    preludeEdge(f, name, i) and
    f = getRelevantLocatable(defaultDebugStartLine())
  }

  string debugGetCanonicalPath(ItemNode i, Crate c) {
    result = i.getCanonicalPath(c) and
    i = getRelevantLocatable(defaultDebugStartLine())