Remove ARM64 special handling from install-dotnet pipeline template

[paulmedynski]

Description

The UseDotNet@2 task historically installed the x86 build on Windows ARM64 hosts because it detected the architecture from the x86 pipeline agent's PROCESSOR_ARCHITECTURE. To work around this, our install-dotnet.yml template forked to a custom install-dotnet-arm64.ps1 script for ARM64.

That bug is now fixed: UseDotNet@2 v271+ correctly detects win-arm64 and installs the matching SDK/runtime (see azure-pipelines-tasks#20300, fixed by #21801). We no longer need the workaround.

Changes (engineering/CI only — no product code or API changes):

• install-dotnet.yml — Removed the ARM64 branch and the custom PowerShell@2 installer step. A single UseDotNet@2 path now handles all architectures (ARM64 auto-detected). Replaced the architecture enum (x64/x86/arm64) with a forceX86 boolean, since forcing an x86 cross-install was the only remaining behavior the parameter controlled.
• Deleted install-dotnet-arm64.ps1 — no longer referenced.
• ci-run-tests-job.yml — Always passes runtimes in the UseDotNet@2 version format ([8.x, 9.x]); removed the now-unused isArm64 parameter; the x86 test install now uses forceX86: true.
• ci-run-tests-stage.yml — Removed the isArm64 passthroughs.
• dotnet-sqlclient-ci-core.yml — Removed isArm64: true from the windows_azure_arm64_sql matrix entry (the ARM64 agent is still selected via pool/images).

Net: 5 files changed, ~390 lines removed.

Issues

Relates to the upstream fix in microsoft/azure-pipelines-tasks#20300.

Testing

See the legacy PR pipelines for successful ARM64 and x86 runs. The modern sqlclient-pr pipeline confirms no regressions.

We see the ARM64 SDK being installed now via the latest UseDotNet@2 task:

Primary:win-arm64
Detected platform (Primary): win-arm64
Version 10.0.301 was not found in cache.
Downloading: https://builds.dotnet.microsoft.com/dotnet/Sdk/10.0.301/dotnet-sdk-10.0.301-win-arm64.zip

Same with the runtimes:

Primary:win-arm64
Detected platform (Primary): win-arm64
Downloading: https://builds.dotnet.microsoft.com/dotnet/Runtime/8.0.28/dotnet-runtime-8.0.28-win-arm64.zip

We see this confirmed by the step that reports the installed SDKs and Runtimes:

.NET SDK:
 Version:           10.0.301
 Commit:            96856fd726
 Workload version:  10.0.300-manifests.b0c14421
 MSBuild version:   18.6.4+96856fd72

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.26200
 OS Platform: Windows
 RID:         win-arm64
 Base Path:   D:\a\_work\_tool\dotnet\sdk\10.0.301\

Host:
  Version:      10.0.9
  Architecture: arm64
  Commit:       901ca94124

Pipeline Runs

• Legacy:
  • PR-SqlClient-Project: 19403
  • PR-SqlClient-Package: 19403
  • CI-SqlClient: 19522
  • CI-SqlClient-Package: 19521
  • MDS Main CI: Same as CI-SqlClient.
  • MDS Main CI-Package: Same as CI-SqlClient-Package.
• Modern:
  • sqlclient-pr: 19403
  • sqlclient-stress: 19402
  • sqlclient-package: 19501
  • sqlclient-kerberos: 20260714.4 (Failed due to environmental issues; .NET SDK/Runtime installs and builds succeeded.)
• Official:
  • sqlclient-non-official: 26195.2
• Classic:
  • These pipelines do not use install-dotnet.yml, but they do use the UseDotNet@2 task.
  • None of them specify ARM64 or x86 architecture, so they don't require any updates, but we will run them if possible just for fun.
  • Localization-CI: Only uses GitHub dotnet/SqlClient main - cannot be run against this PR branch.
  • sqlclient-fuzztest: Uses published SqlClient NuGet packages - cannot be run against this PR branch.
  • Test-SqlClient-Managed-Instance: 160698
  • Docs-Build-Pack-Publish: 26195.2

[Copilot]

Pull request overview

This PR simplifies the Azure DevOps pipeline .NET installation flow by removing the ARM64-specific workaround script and relying on fixed UseDotNet@2 behavior to install the native SDK/runtime on Windows ARM64 agents.

Changes:

• Removed ARM64 branching and custom PowerShell installer usage; standardized on UseDotNet@2 for all architectures.
• Replaced the install template’s architecture enum with a forceX86 boolean to support x86 cross-install scenarios.
• Removed isArm64 wiring across the CI core pipeline matrix and test stage/job templates, and normalized runtime version formats to [8.x, 9.x].

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
eng/pipelines/dotnet-sqlclient-ci-core.yml	Removes isArm64 from the ARM64 matrix entry; ARM64 selection remains via pool/image.
eng/pipelines/common/templates/stages/ci-run-tests-stage.yml	Stops passing isArm64 into the test job template.
eng/pipelines/common/templates/jobs/ci-run-tests-job.yml	Drops isArm64 parameter usage; always installs runtimes via UseDotNet@2 format; uses forceX86: true for x86 installs.
eng/pipelines/common/steps/install-dotnet.yml	Removes ARM64 special-casing and introduces forceX86 parameter for x86 cross-install behavior.
eng/pipelines/common/steps/install-dotnet-arm64.ps1	Deletes the now-unreferenced ARM64 install script.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.34%. Comparing base (fdebcd2) to head (3c39cac).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4442      +/-   ##
==========================================
- Coverage   65.83%   64.34%   -1.50%     
==========================================
  Files         287      287              
  Lines       43763    66952   +23189     
==========================================
+ Hits        28812    43081   +14269     
- Misses      14951    23871    +8920     

Flag	Coverage Δ
CI-SqlClient	65.83% <ø> (-0.01%)	⬇️
PR-SqlClient-Project	63.95% <ø> (?)

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[mdaigle]

All looks good. Can you please link passing CI and non-official runs?

Do we need to update other pipelines like MI, kerberos, etc.?

[paulmedynski]

All pipelines that install .NET SDKs and/or Runtimes have been noted in the PR description, with links to completed or in-progress runs.