[NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android by sbomer · Pull Request #35071 · dotnet/maui

sbomer · 2026-04-21T23:16:47Z

Note

This PR was created with assistance from AI.

Summary

Add _PrepareTrimConfiguration to _MauiPrepareForILLink's BeforeTargets so that RuntimeHostConfigurationOption items (like IsHybridWebViewSupported) are added before the runtime's internal target snapshots them into _TrimmerFeatureSettings.

Problem

dotnet/runtime PR #124801 moved the RuntimeHostConfigurationOption → _TrimmerFeatureSettings conversion from PrepareForILLink into an earlier internal target (_PrepareTrimConfiguration). MAUI's _MauiPrepareForILLink hooks BeforeTargets="PrepareForILLink", which now fires after the snapshot. As a result, ILC never receives --feature flags for MAUI's feature switches on Android NativeAOT, causing spurious IL3050 warnings for HybridWebViewHandler.

Fix

Add _PrepareTrimConfiguration to the BeforeTargets list of _MauiPrepareForILLink. This ensures MAUI's RuntimeHostConfigurationOption items are present when the snapshot runs.

This is a temporary workaround using the internal target name. The runtime fix (dotnet/runtime#127253) renames this to the public PrepareTrimConfiguration. Once that flows, this should be updated to BeforeTargets="PrepareTrimConfiguration;PrepareForILLink;...".

Verified

Tested with a MAUI Android NativeAOT app using the android-il3050 local build:

Before: --feature:Microsoft.Maui.RuntimeFeature.IsHybridWebViewSupported=false missing → IL3050
After: --feature flag present → IL3050 suppressed

Workaround for dotnet/runtime#127017

cc @sbomer @simonrozsival

github-actions · 2026-04-21T23:16:56Z

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 35071

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 35071"

Add _PrepareTrimConfiguration to _MauiPrepareForILLink's BeforeTargets so that RuntimeHostConfigurationOption items (like IsHybridWebViewSupported) are added before the runtime's _PrepareTrimConfiguration target snapshots them into _TrimmerFeatureSettings. Without this, ILC never receives --feature flags for MAUI's feature switches on Android where RunILLink=true, causing spurious IL3050 warnings. This is a temporary workaround using the internal target name. Once dotnet/runtime ships the fix (renaming to public PrepareTrimConfiguration), this should be updated to BeforeTargets="PrepareTrimConfiguration". Workaround for dotnet/runtime#127017 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Assisted-by: Claude:claude-opus-4.6-1m

Copilot

Pull request overview

Updates MAUI’s transitive MSBuild targets so MAUI’s RuntimeHostConfigurationOption feature switches are applied early enough for Android NativeAOT trimming to pick them up, avoiding spurious IL3050 warnings.

Changes:

Hook _MauiPrepareForILLink to run before the runtime’s earlier trim-configuration snapshot target (_PrepareTrimConfiguration).

Copilot · 2026-04-21T23:18:44Z

  </Target>

-  <Target Name="_MauiPrepareForILLink" BeforeTargets="PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">
+  <Target Name="_MauiPrepareForILLink" BeforeTargets="_PrepareTrimConfiguration;PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">


Consider adding the public target name PrepareTrimConfiguration to the BeforeTargets list as well (e.g., PrepareTrimConfiguration;_PrepareTrimConfiguration;...). This keeps the workaround working both before and after the runtime target rename (and is safe because MSBuild ignores non-existent targets).

Suggested change

<Target Name="_MauiPrepareForILLink" BeforeTargets="_PrepareTrimConfiguration;PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">

<Target Name="_MauiPrepareForILLink" BeforeTargets="PrepareTrimConfiguration;_PrepareTrimConfiguration;PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">

jonathanpeppers

Looks OK, I just had one question.

jonathanpeppers · 2026-04-24T19:53:48Z

  </Target>

-  <Target Name="_MauiPrepareForILLink" BeforeTargets="PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">
+  <Target Name="_MauiPrepareForILLink" BeforeTargets="_PrepareTrimConfiguration;_GenerateRuntimeConfigurationFilesInputCache;XamlC">


Are we OK to use a private target name, like _PrepareTrimConfiguration, any chance it would be renamed?

It could be renamed or modified - this is relying on an implementation detail. See #35163.

I considered making PrepareTrimConfiguration public in dotnet/runtime#127253 but I no longer think that's a good idea.

@sbomer

…Android (#35094) > [!NOTE] > This PR was created with assistance from AI. Port of #35071 to the `net11.0` branch. ## Summary Add `_PrepareTrimConfiguration` to `_MauiPrepareForILLink`'s `BeforeTargets` so that `RuntimeHostConfigurationOption` items (like `IsHybridWebViewSupported`) are added before the runtime's internal target snapshots them into `_TrimmerFeatureSettings`. ## Problem dotnet/runtime PR #124801 moved the `RuntimeHostConfigurationOption` → `_TrimmerFeatureSettings` conversion from `PrepareForILLink` into an earlier internal target (`_PrepareTrimConfiguration`). MAUI's `_MauiPrepareForILLink` hooks `BeforeTargets="PrepareForILLink"`, which now fires *after* the snapshot. As a result, ILC never receives `--feature` flags for MAUI's feature switches on Android NativeAOT, causing spurious IL3050 warnings for `HybridWebViewHandler`. This is the branch (`net11.0`, SDK `11.0.100-preview.3.26203.107`) where the bug manifests — the .NET 11 SDK has `_PrepareTrimConfiguration`. ## Fix Remove `PrepareForILLink` from `BeforeTargets` (redundant — it's a transitive dependent of `_PrepareTrimConfiguration`) and add `_PrepareTrimConfiguration` instead. This ensures MAUI's `RuntimeHostConfigurationOption` items are present when the snapshot runs. **Temporary workaround** using the internal target name. The runtime fix (dotnet/runtime#127253) renames this to the public `PrepareTrimConfiguration`. Once that flows, update to `BeforeTargets="PrepareTrimConfiguration"`. Workaround for dotnet/runtime#127017 cc @sbomer @simonrozsival Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

PureWeen · 2026-04-27T11:45:27Z

@sbomer main is net10.0 only and will never bet net11.0 until we go GA with net11.0 and just merge the whole thing back into main

do we need this PR?

	Without PR	With PR	Verdict
main (net10.0 SDK)	✅ AOT passes (60/60)	❌ AOT fails (4 IL3050)	PR #35071 BREAKS main
net11.0 (net11.0 SDK)	❌ AOT fails (IL3050)	✅ AOT passes (18/18)	PR #35094 FIXES net11.0

The same 1-line change (PrepareForILLink → _PrepareTrimConfiguration) has opposite effects on the two branches because the SDK build pipeline ordering differs:

On main (net10.0 SDK): PrepareForILLink works correctly as the hook point. Changing to _PrepareTrimConfiguration means the feature switches never get set → IL3050 appears.
On net11.0 (net11.0 SDK): PrepareForILLink runs too late (due to runtime#124801 changes). _PrepareTrimConfiguration runs earlier → feature switches work → IL3050 gone.

Bottom line:

Merge [net11.0][NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android #35094 (net11.0) ✅
Close [NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android #35071 (main) ❌ — it regresses main, which doesn't have this problem

sbomer · 2026-04-27T18:18:31Z

Cloing this since the fix is in net11.0 and main is net10.0. only.

Copilot AI review requested due to automatic review settings April 21, 2026 23:16

Copilot started reviewing on behalf of sbomer April 21, 2026 23:17 View session

Copilot AI reviewed Apr 21, 2026

View reviewed changes

sbomer force-pushed the dev/sbomer/maui-il3050 branch from dede0fd to 6d0657c Compare April 21, 2026 23:20

build-analysis Bot mentioned this pull request Apr 22, 2026

[Android NativeAOT] IL3050 HybridWebViewHandler warning — ILC regression in runtime#124801 #35025

Closed

This was referenced Apr 22, 2026

[repo-status] Daily Repo Status - April 22, 2026 #35075

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[PR Review Queue] 2026-04-22 #35078

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sbomer mentioned this pull request Apr 22, 2026

[net11.0][NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android #35094

Merged

This was referenced Apr 23, 2026

[PR Review Queue] 2026-04-23 #35101

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[PR Review Queue] 2026-04-24 #35123

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jonathanpeppers approved these changes Apr 24, 2026

View reviewed changes

github-actions Bot mentioned this pull request Apr 27, 2026

[PR Review Queue] 2026-04-27 #35146

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sbomer closed this Apr 27, 2026

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[NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android#35071

[NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android#35071
sbomer wants to merge 1 commit intomainfrom
dev/sbomer/maui-il3050

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	<Target Name="_MauiPrepareForILLink" BeforeTargets="_PrepareTrimConfiguration;PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">
	<Target Name="_MauiPrepareForILLink" BeforeTargets="PrepareTrimConfiguration;_PrepareTrimConfiguration;PrepareForILLink;_GenerateRuntimeConfigurationFilesInputCache;XamlC">

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sbomer commented Apr 21, 2026

Summary

Problem

Fix

Verified

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