Summary
Since the pool leak validation infrastructure was merged in #82784 (May 15), multiple CI builds are failing due to a pool leak of ArrayBuilder<PENamedTypeSymbol> at ArrayBuilder.cs:504. The leak is reproducible across main and multiple unrelated PRs, indicating a pre-existing issue now caught by the new validation.
Error Message
Pool leak detected! The following pooled objects were not returned:
Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder`1[Microsoft.CodeAnalysis.CSharp.Symbols.Metadata.PE.PENamedTypeSymbol] (from ArrayBuilder.cs:504)
The leaked object count varies between 1 and 274 across runs.
Failing Tests
TestNoSuppression_CompilerSemanticErrorTestSuppression_CompilerSyntaxDeclarationError_SuppressWarningTriggeredByGenerator(skipAnalyzers: False)TestSuppression_CompilerSyntaxDeclarationError_SuppressWarningTriggeredByGenerator(skipAnalyzers: True)
Impacted Builds (last 3 days)
| Build ID |
Branch |
PR |
Finish Time (UTC) |
Leaked Count |
| 1424014 |
refs/pull/83643/merge |
#83643 |
2026-05-18 02:37 |
1 |
| 1423929 |
refs/pull/83740/merge |
#83740 |
2026-05-17 21:12 |
1 |
| 1423737 |
refs/heads/main |
— |
2026-05-17 14:09 |
241 |
| 1423705 |
refs/pull/83738/merge |
#83738 |
2026-05-17 12:21 |
260 |
| 1423487 |
refs/pull/83736/merge |
#83736 |
2026-05-17 00:31 |
91 |
| 1423441 |
refs/pull/83732/merge |
#83732 |
2026-05-16 20:28 |
241 |
| 1423344 |
refs/pull/83712/merge |
#83712 |
2026-05-16 16:05 |
205 |
| 1423227 |
refs/heads/main |
— |
2026-05-16 13:07 |
61 |
| 1423155 |
refs/pull/83693/merge |
#83693 |
2026-05-16 10:33 |
274 |
| 1423153 |
refs/heads/main |
— |
2026-05-16 08:33 |
137 |
Context
This leak appears to have existed prior to #82784 but was not detected until pool validation was enabled in compiler tests. The failures occur across unrelated PRs and main, confirming this is not caused by any specific recent change.
cc @jjonescz
Summary
Since the pool leak validation infrastructure was merged in #82784 (May 15), multiple CI builds are failing due to a pool leak of
ArrayBuilder<PENamedTypeSymbol>atArrayBuilder.cs:504. The leak is reproducible acrossmainand multiple unrelated PRs, indicating a pre-existing issue now caught by the new validation.Error Message
The leaked object count varies between 1 and 274 across runs.
Failing Tests
TestNoSuppression_CompilerSemanticErrorTestSuppression_CompilerSyntaxDeclarationError_SuppressWarningTriggeredByGenerator(skipAnalyzers: False)TestSuppression_CompilerSyntaxDeclarationError_SuppressWarningTriggeredByGenerator(skipAnalyzers: True)Impacted Builds (last 3 days)
Context
This leak appears to have existed prior to #82784 but was not detected until pool validation was enabled in compiler tests. The failures occur across unrelated PRs and
main, confirming this is not caused by any specific recent change.cc @jjonescz