Scanned 77 roslyn-CI builds from 2026-06-03 to 2026-06-05. Found 17 test runs with < 10 total tests (excluding macOS empty runs).
These appear to be AzDO retry summary runs that aggregate failures without real test execution.
| Build | Run ID | Run Name | Total | Failed | Duration |
|---|
The x86 test host for Microsoft.CodeAnalysis.CSharp.EditorFeatures.UnitTests (net472) crashes
with an OutOfMemoryException during CI runs. The x86 process has a 4 GB virtual address (VA)
space limit, and the test host exceeds this limit during the ~16,591 test run.
Two testhost.net472.x86.exe processes crashed with OOM on a Helix CI agent. Root cause: Roslyn's TemporaryStorageService accumulated 525+ unique 8 MB memory-mapped file (MMF) sections, consuming ~4,200 MB of virtual address space — exceeding the x86 process limit of 4 GB.
| Property | Value |
|---|
| using System.Diagnostics; | |
| using System.Net.Http.Headers; | |
| using System.Text.Json; | |
| using System.Text.RegularExpressions; | |
| /// <summary> | |
| /// Proves that AzDO's reported duration for grouped parameterized tests is NOT | |
| /// the sum of individual variant execution times. | |
| /// | |
| /// Approach: |
Date range: May 18–20, 2026 Pipeline: roslyn-CI (dotnet/roslyn)
Over the last 2 days, 9 out of 140 roslyn-CI builds (6.4%) experienced at least one Helix job timeout. These 9 builds produced a total of 23 individual job timeout occurrences. The issue is systemic and not isolated to any single PR — it affects both PR validation builds and main branch builds alike. The most frequently affected leg is Test_Windows_CoreClr_Release, which timed out in 8 of the 9 affected builds.
Overall Health: 🔴 RED (Critical — Infrastructure Failure + Masked Regression)
The pipeline remains critically impaired. 7 consecutive main branch failures since the last success (1425328, May 18 2:57 PM PDT). Only 3 out of 25 main builds succeeded in the last 3 days (12% success rate).
Overall Health: 🔴 RED — PIPELINE NON-OPERATIONAL (60+ HOURS)
Current Status:
Analyzed all 16 net472-only .UnitTests projects in dotnet/roslyn. Excluded 9 with Visual Studio/WPF hard dependencies. 7 candidates remain.
| Project | Notes |
|---|---|
CodeStyle/CSharp/Tests |
Pure analyzer testing, no VS/WPF deps. Straightforward. |
Features/ExternalAccess/OmniSharpTest |
Minimal deps — OmniSharp.CSharp targets netstandard2.0. Very clean. |
Roslyn's VBCSCompiler process suffers from significant byte[] allocations driven by System.Reflection.Metadata APIs, primarily through BlobBuilder. The goal is to enable a pooling strategy where Roslyn pre-allocates ~4MB of byte[] and PE file writing completes with zero (or near-zero) additional allocations.