Make 'cabal clean' more robust: retry after getting 'Unsatisfied constraints (directory is non empty)' error

[Bodigrim]

I've been testing Cabal HEAD manually and uncovered another case when retrying cabal clean is helpful. This is a follow up to #11604.

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[ffaf1]

Very good.

If this does not make the 3.18 cut, it will have to be rebased.

[Bodigrim]

This still needs one more approval please.

[ulysses4ever]

I must confess this picking and choosing seemingly random error types to retry doesn't look pretty to me. But if it helps the cause, I can live with it ...

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-06-08 11:18 UTC · Rule: default
• ✅ Checks started · on draft merge queue: embarking master (4960764) and #11938 together #11951
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• 🚫 Left the queue — 2026-06-08 12:57 UTC · at 79e93c6bd0d8ba8cf55600a86015a5e7bc9ae56f

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  • Make 'cabal clean' more robust: retry after getting 'Unsatisfied constraints (directory is non empty)' error #11938
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  • Make 'cabal clean' more robust: retry after getting 'Unsatisfied constraints (directory is non empty)' error #11938
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