TEMPORARY: Overlay custom MSBuild for dotnet/msbuild#12927 investigation#66003
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ilonatommy wants to merge 38 commits intodotnet:mainfrom
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TEMPORARY: Overlay custom MSBuild for dotnet/msbuild#12927 investigation#66003ilonatommy wants to merge 38 commits intodotnet:mainfrom
ilonatommy wants to merge 38 commits intodotnet:mainfrom
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Add custom Microsoft.Build.Tasks.Core.dll from the MSBuild team with additional logging to diagnose intermittent MSB3030 'Could not copy file' errors in parallel builds. The DLL is overlaid onto the SDK's copy in eng/build.sh and eng/build.ps1 after SDK initialization, with SHA256 verification output in the build log. DO NOT MERGE - investigation branch only. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Windows PowerShell 5.1 (used on CI agents) only supports 2 arguments to Join-Path. Nest the calls instead. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The env var may not be set in all CI build configurations. Fall back to RepoRoot/.dotnet which configure-toolset.ps1 always forces. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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* NO MERGE *
Scheduled task script that: - Checks Build Analysis check run to see if CI is done - Searches AzDO logs for MSB3030/MSB3026 errors - If not found, merges upstream/main and retriggers CI - If found, logs alert and stops Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
This was referenced Mar 28, 2026
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🚨 MSB3030 "File Not Found" Error Detected (Automated)Build: #1376139 Errors found:
Action required: Collect binlog from this build and share with MSBuild team (@OvesN on dotnet/msbuild#12927). This comment was posted automatically by the CI monitor script. |
This was referenced Apr 19, 2026
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DO NOT MERGE - Investigation branch only
Purpose
Overlay custom
Microsoft.Build.Tasks.Core.dllfrom the MSBuild team to diagnose intermittentMSB3030: Could not copy fileerrors during parallel CI builds.Tracking issue: dotnet/msbuild#12927
Known Build Error: #62807
hits from the known build issue happened on:
So it hits both Linux and Windows build legs, specifically during the large parallel compilation steps (Run build.sh, Run build.cmd, Build Installers). These are the jobs where /m parallelism triggers the race condition. Our overlay covers both build.sh and build.ps1, so we're
covered on all the failing legs.
❯ are these legs running on our playground PR?
What this does
Microsoft.Build.Tasks.Core.dll(with extra logging) toeng/msbuild-bootstrapeng/build.shandeng/build.ps1, overlays the custom DLL onto.dotnet/sdk<version>/Microsoft.Build.Tasks.Core.dllSHA256hashes to the build log so we can verify the overlay workedExpected outcome
=== MSBuild Bootstrap Overlay ===section confirming the DLL was replacedMSB3030 erroroccurs, the binlog will contain additional diagnostic information from the custom MSBuildHow to revert
Close this PR. No repo-wide changes are needed.
This PR should be updated automatically when my devbox's task scheduler detects that CI finished without error that we're waiting for.