fix: clean missing-spec error when a selected vcgen spec fails to apply - #14490
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…pply This PR makes `vcgen` report a clean missing-spec error when the spec it selects for a program turns out not to unify with it, instead of dumping the internal backward rule and its type. The spec discrimination tree over-approximates, so a sole candidate returned by spec selection may not unify with the program. When the selected rule fails to apply, `applySpec` now matches the spec's pattern against the program: if the pattern does not unify, it routes through the same missing-spec handling as every other unmatched-spec case (naming the program and its candidates, or emitting the goal as a verification condition under `-errorOnMissingSpec`); if the pattern does unify, the rule failure is a genuine bug and the original hard error is preserved. The improvement is covered by the updated `recf` expectation in `tests/elab/vcgenUnfoldMatchDef.lean`.
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…pply (#14490) This PR makes `vcgen` report a clean missing-spec error when the spec it selects for a program turns out not to unify with it, instead of dumping the internal backward rule and its type. The spec discrimination tree over-approximates, so a sole candidate returned by spec selection may not unify with the program. When the selected rule fails to apply, `applySpec` now matches the spec's pattern against the program: if the pattern does not unify, it routes through the same missing-spec handling as every other unmatched-spec case; if the pattern does unify, the rule failure is a genuine bug and the original hard error is preserved. The improvement is covered by the updated `recf` expectation in `tests/elab/vcgenUnfoldMatchDef.lean`.
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This PR makes
vcgenreport a clean missing-spec error when the spec it selects for a program turns out not to unify with it, instead of dumping the internal backward rule and its type.The spec discrimination tree over-approximates, so a sole candidate returned by spec selection may not unify with the program. When the selected rule fails to apply,
applySpecnow matches the spec's pattern against the program: if the pattern does not unify, it routes through the same missing-spec handling as every other unmatched-spec case; if the pattern does unify, the rule failure is a genuine bug and the original hard error is preserved. The improvement is covered by the updatedrecfexpectation intests/elab/vcgenUnfoldMatchDef.lean.