fix(module): define GNU dynamic-module error symbols

[thanosapollo]

Why

module-load signals module-open-failed and the other module-load-failed errors (and the dynamic-module runtime signals memory-buffer-too-small and invalid-arity), but none of GNU's dynamic-module error symbols had error-conditions or error-message. A failed dlopen therefore surfaced as (error "Invalid error symbol" module-open-failed) instead of a catchable module-open-failed, and handlers for module-load-failed never matched. The MELPA parity notes already record this symptom (Invalid error symbol: module-open-failed in the closql / sqlite3-api case).

Change

Register the complete syms_of_module set from GNU src/emacs-module.c, with GNU's condition lists and messages, in both the obarray error table and ErrorRegistry:

Symbol	Conditions	Message
module-out-of-memory	error	Module out of memory
module-load-failed	error	Module load failed
module-open-failed	module-load-failed error	Module could not be opened
module-not-gpl-compatible	module-load-failed error	Module is not GPL compatible
missing-module-init-function	module-load-failed error	Module does not export an initialization function
module-init-failed	module-load-failed error	Module initialization failed
invalid-arity	error	Invalid function arity
memory-buffer-too-small	error	Memory buffer too small

No module-loading behaviour changes; only the error symbols' properties are defined.

Verification

New tests in neovm-core (runtime/errors/tests/mod.rs, Nextest names emacs_core::errors::tests::*):

• registry_module_load_failed_family checks the ErrorRegistry hierarchy.
• module_error_symbols_match_gnu_emacs_module_c evaluates in the bootstrap evaluator: module-load of a missing file is caught by a module-load-failed handler as module-open-failed; each symbol's error-conditions / error-message equals GNU's; and error-message-string formats a module-open-failed error.

Both fail on the base commit and pass with this change. Focused Linux run with Nextest:

cargo nextest run -p neovm-core --lib -E 'test(~emacs_core::errors::) | test(~dynamic_module) | test(~module_load) | test(~module_open)'

102 tests run, 102 passed (the existing error-table and dynamic-module tests plus the two new ones). cargo fmt --check -p neovm-core passes. This is a focused selection, not a full-workspace or hosted-CI result.

Assistance

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ℹ️ Recent review info

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• Configuration used: Repository UI
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• Run ID: a247d0a9-7c88-4f96-951a-856eaa042baf

📥 Commits

Reviewing files that changed from the base of the PR and between 7764ef7 and 034f17a.

📒 Files selected for processing (2)

• crates/neovm-core/src/emacs_core/runtime/errors/mod.rs
• crates/neovm-core/src/emacs_core/runtime/errors/tests/mod.rs

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📝 Walkthrough

Walkthrough

The standard error registry now includes eight dynamic-module error conditions with defined parent relationships. New tests check their inheritance, condition lists, messages, and formatted error output.

Changes

Dynamic-module errors

Layer / File(s)	Summary
Register and verify module errors crates/neovm-core/src/emacs_core/runtime/errors/mod.rs, crates/neovm-core/src/emacs_core/runtime/errors/tests/mod.rs	The standard error declarations and hierarchy add eight dynamic-module error conditions. Tests check condition inheritance and lists, Lisp-visible messages, and formatted module-open-failed output.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: eval-exec

Merge Risk: ⚪ Minimal · up to 034f1

No actionable issue is identified in the module-error definitions or tests. The change is mergeable after normal checks.

Security Architecture Review

Security architecture risk: ⚪ Minimal · up to 034f1

The change makes existing module failures catchable under the intended error names without changing module-loading permissions or execution authority. No material new security risk was identified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The introduced behavior affects failure classification and handler selection in the invoking evaluator. Native modules retain their existing host-process execution authority; the registrations do not create a new module-loading entrypoint or confer additional privileges.

Trust Boundaries and Controls

• observed — The loader still returns failures when library opening, the GPL marker check, or initialization-symbol lookup fails. Registering those failure symbols changes their catchability, not whether the loader advances past those checks.

Resilience and Maintainability Implications

• inferred — Initialization failure, pending non-local exit, or interruption returns before successful-module insertion. Native initialization is not transactional with evaluator state, so prior side effects need not be undone. This limitation predates the PR: generic error handlers could already catch the base’s invalid-symbol error and continue after failure.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 80.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 5 functions across 2 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the change: defining GNU dynamic-module error symbols.
Description check	✅ Passed	The description explains the missing error properties, the symbols and condition hierarchies added, and the reported tests. It is directly related to the changeset.

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✨ Finishing Touches 💡 1

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