[adilalperenciftci]

Summary

I traced a lexical-containment gap to tuple slot binding. Plain reads and assignments honored hide and seal except, but name, _ = tuple() looked up outer bindings directly and could re-bind a name excluded by the current scope.

This change checks each named destructure slot before re-binding it. An outer name blocked by hide or seal except is rejected, while a visible local below the directive and a genuinely new local inside a sealed block retain their existing behavior.

Verification

• BEFORE: hidden and sealed-out outer names were both writable through tuple destructuring.
• AFTER: both cases are rejected; the local-binding control still compiles.
• sh tests/integration/hide_seal_directives/test_hide_reject.sh (18 passed)
• make check-changelog
• make check-tests
• make test (634 passed)

Signed-off-by: Adil Alperen Çiftci adilalperenciftci@users.noreply.github.com

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[adilalperenciftci]

Rebased onto current main at 356bfd8e. The test-driver conflict was additive: I retained main's four DSL-receiver containment cases and placed the three tuple-destructuring cases after them.

Ubuntu VM verification:

• hide_seal_directives: 22 passed, 0 failed.
• Hidden outer tuple rebinding: rejected.
• Sealed-out outer tuple rebinding: rejected.
• Visible local and fresh tuple bindings inside the sealed block: accepted.
• make check-tests: passed.
• make check-changelog: passed.
• make test: 634 passed, 0 failed.

Updated head: 6171f7ca.

[paul-hammant]

Thanks @adilalperenciftci! This landed in #3474, which batched nine of your PRs and merged on 2026-10-30 (ca1dae7d). Your commit went in unchanged with your authorship, so this PR is superseded, and I'm closing it.