Remove IsTrimmable=false from assemblies that are already AotCompatible by kotlarmilos · Pull Request #34573 · dotnet/maui

kotlarmilos · 2026-03-19T15:49:30Z

Description

These four assemblies already set IsAotCompatible=true (which implies IsTrimmable=true via the SDK's Microsoft.NET.Publish.targets), but the explicit IsTrimmable=false overrides that and prevents them from being trimmed in SdkOnly link mode.

The IsTrimmable=false was added in PR #10647 to lock down the value, but it was never updated when these assemblies were made AOT-compatible in PRs #21076 and #21505.

Removing IsTrimmable=false lets IsAotCompatible=true take effect, allowing these assemblies to be trimmed in SdkOnly link mode.

Affected assemblies:

Microsoft.Maui (Core.csproj)
Microsoft.Maui.Controls (Controls.Core.csproj)
Microsoft.Maui.Graphics (Graphics.csproj)
Microsoft.Maui.Controls.Xaml (Controls.Xaml.csproj)

Context

While working on reducing Debug bundle size for CoreCLR R2R builds in dotnet/macios (dotnet/macios#24909), we found these assemblies are the main ones not being trimmed in SdkOnly mode.

These assemblies already set IsAotCompatible=true (which implies IsTrimmable=true via the SDK), but the explicit IsTrimmable=false overrides that and prevents them from being trimmed in SdkOnly mode. The IsTrimmable=false was added in PR dotnet#10647 (Oct 2022) to lock down the value, but it was never updated when these assemblies were made AOT-compatible in PRs dotnet#21076 and dotnet#21505 (2024). Removing IsTrimmable=false lets IsAotCompatible=true take effect, allowing these assemblies to be trimmed in SdkOnly link mode. This reduces bundle size for both Debug and Release builds. Affected assemblies: - Microsoft.Maui (Core.csproj) - Microsoft.Maui.Controls (Controls.Core.csproj) - Microsoft.Maui.Graphics (Graphics.csproj) - Microsoft.Maui.Controls.Xaml (Controls.Xaml.csproj) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-03-19T15:49:42Z

🚀 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 -- 34573

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 34573"

Copilot

Pull request overview

This PR aligns trimming behavior with existing AOT-compatibility declarations by removing explicit IsTrimmable=false overrides from key MAUI assemblies, so IsAotCompatible=true can cause them to be treated as trimmable (notably impacting SdkOnly link mode scenarios).

Changes:

Removed <IsTrimmable>false</IsTrimmable> from Microsoft.Maui (Core).
Removed <IsTrimmable>false</IsTrimmable> from Microsoft.Maui.Controls and Microsoft.Maui.Controls.Xaml.
Removed <IsTrimmable>false</IsTrimmable> from Microsoft.Maui.Graphics.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/Core/src/Core.csproj	Removes the explicit `IsTrimmable=false` override so the existing non-netstandard `IsAotCompatible=true` can drive trimming.
src/Controls/src/Core/Controls.Core.csproj	Same: drops the override to allow trimming in configurations where `IsAotCompatible=true` is already set.
src/Controls/src/Xaml/Controls.Xaml.csproj	Same: removes `IsTrimmable=false` to let `IsAotCompatible=true` imply trimming for applicable TFMs.
src/Graphics/src/Graphics/Graphics.csproj	Same: removes `IsTrimmable=false` so trimming can apply when `IsAotCompatible=true` is set.

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rolfbjarne · 2026-03-20T09:27:51Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-03-20T09:28:10Z

Azure Pipelines successfully started running 2 pipeline(s).

kotlarmilos · 2026-03-24T18:26:27Z

CI failures (ui tests timeouts, mobile device test crashes) are pre-existing net11.0 baseline issues unrelated to this PR

PureWeen · 2026-03-24T20:44:48Z

Shell MenuItem Trimming Regression Analysis

Investigation of the 34 VerifyShellFlyout_* Android test failures across all 6 Shell test runs.

Root Cause

Removing IsTrimmable=false makes MAUI assemblies eligible for ILLink trimming in Android Release builds (SdkOnly link mode). This causes Shell MenuItem elements to silently disappear from the flyout drawer — no runtime exception, no MissingMethodException, the items simply never render.

Evidence from ADO Test Attachments (Build 1344675)

Logcat analysis of Order 1 test (VerifyShellFlyout_Header, 1.3MB logcat):

Step	Result
Navigate to Shell Feature Matrix page	✅ Found `GoToTestButton`, `SearchBar`
Tap `ShellFlyoutButton` → Shell page loads	✅
Tap Options → FlyoutHeader → Apply	✅ All elements found and tapped
Open flyout drawer (hamburger icon)	✅ `"Open navigation drawer"` found
`WaitForElement("Header")` in flyout	✅ Found — drawer is open
`WaitForElement("OpenFlyout")` MenuItem	❌ 0 matches by ID and XPath

Page source XML at failure shows what is rendered vs what is not:

✅ Renders in flyout	❌ Missing from flyout
`Header` (FlyoutHeader)	`OpenFlyout` (MenuItem)
`FlyoutItems` label	`FlyoutBehavior` (MenuItem)
Home, Reports, Options (ShellContent tabs)	Any `MenuItem`-type elements

No managed exceptions in logcat — no TypeLoadException, MissingMethodException, or MissingMemberException. The app runs fine, Shell navigation works, 152 other Shell tests pass. Only the MenuItem rendering path is broken.

Failure Pattern

34 tests fail — all reference OpenFlyout AutomationId (a <MenuItem>)
5 tests pass — the only ones that never touch OpenFlyout
100% reproducible across all 6 Android Shell runs
Order 1 fails with NullReferenceException at Tap(OpenFlyout); Orders 2-34 cascade with TimeoutException

Suspected Trimmed Code Paths

The linker likely trims code in the MenuItem→flyout rendering pipeline:

Shell.cs line 694: if (bo is IMenuItemController) — conditional template selection for MenuItems
Shell.cs line 884: case MenuItem m: — MenuItem activation handler
ShellFlyoutItemsManager.AddMenuItems() — adds MenuItem items to the flyout collection
MenuShellItem (internal) — wrapper created via implicit operator
BaseShellItem.CreateDefaultFlyoutItemCell() — DataTemplate with Grid/Label/Image used for flyout item rendering

Shell navigation items (ShellContent, ShellSection) render through a different code path than MenuItem, which is why tabs work but MenuItems don't.

Recommendation

The PR may need [DynamicDependency] or [DynamicallyAccessedMembers] annotations on the MenuItem rendering paths to preserve them through ILLink, or the trimming scope needs to be narrowed for Shell-related assemblies.

MenuShellItem is an internal type that wraps MenuItem for flyout rendering. When MAUI assemblies become trimmable (IsTrimmable=true), the ILLink trimmer can strip MenuShellItem and related code paths that are only reached through event-driven and interface-dispatch patterns the linker cannot statically trace. Add [DynamicDependency] on Shell constructor and ShellItem implicit operator to preserve MenuShellItem and its members through trimming. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

kotlarmilos · 2026-03-25T14:29:31Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-03-25T14:29:47Z

Azure Pipelines successfully started running 2 pipeline(s).

Add [UnconditionalSuppressMessage] for IL2026, IL2111, and IL3050 on Shell() constructor and ShellItem.op_Implicit(MenuItem). The warnings originate from the TypeConverter base class hierarchy (ShellItemConverter : TypeConverter) whose inherited members like GetProperties/GetEditor carry RequiresUnreferencedCode. These base methods are never called by MAUI - ShellItemConverter only overrides CanConvertFrom/To and ConvertFrom/To. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…:kotlarmilos/maui into dev/miloskotlar/remove-istrimmable-false

kotlarmilos · 2026-04-14T09:47:18Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-04-14T09:47:36Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-04-17T21:36:18Z

/rebase

PureWeen · 2026-04-17T21:41:01Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-04-17T21:41:19Z

Azure Pipelines successfully started running 2 pipeline(s).

…/remove-istrimmable-false

kotlarmilos · 2026-04-20T06:27:40Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-04-20T06:27:55Z

Azure Pipelines successfully started running 2 pipeline(s).

…r/remove-istrimmable-false

kotlarmilos · 2026-04-27T12:15:41Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-04-27T12:15:59Z

Azure Pipelines successfully started running 2 pipeline(s).

Two regressions vs net11.0 baseline were observed on PR dotnet#34573: 1. Android Core CoreCLR: ImageSourceServiceTests.ReleasingImageSourceReturnsDifferentBitmap asserts that a bitmap is collectible after Dispose. Trim/AOT codegen can keep locals rooted across the GC fence, causing Glide's MemoryCache to retain the bitmap. Fix: hoist the load+dispose into a [MethodImpl(NoInlining)] helper so the IImageSourceServiceResult/Drawable locals leave scope before TryCollectFile runs. This mirrors the established AOT-friendly memory test pattern in MAUI (see UIViewSubclassTests / CALayerAutosizeToSuperLayerBehaviorTests). 2. Windows Controls.DeviceTests-packaged hang (2h timeout, exit -3): cannot be reproduced or root-caused without a Windows machine. Conservatively keep IsTrimmable=false on Microsoft.Maui.Controls.Xaml until the hang is rooted out; Core, Controls.Core and Graphics still get their trim opt-in from this PR. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

kotlarmilos · 2026-04-28T10:36:44Z

/azp run maui-pr-devicetests,maui-pr-uitests

azure-pipelines · 2026-04-28T10:36:59Z

Azure Pipelines successfully started running 2 pipeline(s).

kotlarmilos · 2026-04-29T08:27:50Z

@PureWeen Ready for review, the remaining maui-pr-devicetests and maui-pr-uitests failures are BlazorWebView Android tests hitting "Failed to fetch", and infrastructure osx.26.arm64.open queue issues.

Copilot AI review requested due to automatic review settings March 19, 2026 15:49

kotlarmilos changed the base branch from main to net11.0 March 19, 2026 15:50

Copilot AI reviewed Mar 19, 2026

View reviewed changes

kotlarmilos requested review from jonathanpeppers, rolfbjarne and simonrozsival March 19, 2026 15:52

kotlarmilos self-assigned this Mar 19, 2026

kotlarmilos mentioned this pull request Mar 19, 2026

[net11.0] Fully trim assemblies in R2R image when using SdkOnly link mode in Debug dotnet/macios#24909

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github-actions Bot mentioned this pull request Mar 20, 2026

[repo-status] 🌟 Daily Repo Status - March 20, 2026 #34578

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This was referenced Mar 20, 2026

System.TimeoutException #33245

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CI UItests failure System.TimeoutException : Timed out waiting for element... #33220

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Cannot find 'arm64-v8a' device dotnet/dnceng#2284

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github-actions Bot mentioned this pull request Mar 21, 2026

[repo-status] 🌟 Daily Repo Status - March 21, 2026 #34588

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build-analysis Bot mentioned this pull request Mar 23, 2026

[MacCatalyst] WebViewShouldLoadEncodedUrl flaky on macOS 26 Helix queue (TimeoutException) #34577

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kotlarmilos mentioned this pull request Mar 24, 2026

[clr-ios] App size improvements on iOS for CoreCLR with R2R configuration dotnet/runtime#124212

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10 tasks

kotlarmilos and others added 2 commits March 25, 2026 10:06

Merge branch 'net11.0' into dev/miloskotlar/remove-istrimmable-false

32ae3cd

Merge branch 'dev/miloskotlar/remove-istrimmable-false' of github.com…

4213152

…:kotlarmilos/maui into dev/miloskotlar/remove-istrimmable-false

This was referenced Apr 18, 2026

[Known Build Error] iOS UITest screenshot baseline mismatches after ACES pool migration #33879

Closed

[net11.0] Screenshot baseline mismatches after main merge (Shell, TabbedPage, Image, Flyout) #34586

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Merge branch 'net11.0' of github.com:dotnet/maui into dev/miloskotlar…

6b19868

…/remove-istrimmable-false

github-actions Bot mentioned this pull request Apr 20, 2026

[PR Review Queue] 2026-04-20 #35039

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Me`rge branch 'net11.0' of github.com:dotnet/maui into dev/miloskotla…

0e05d12

…r/remove-istrimmable-false

kotlarmilos mentioned this pull request Apr 29, 2026

Re-enable trimming for Microsoft.Maui.Controls.Xaml #35206

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github-actions Bot mentioned this pull request Apr 29, 2026

[PR Review Queue] 2026-04-29 #35207

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PureWeen approved these changes Apr 30, 2026

View reviewed changes

PureWeen merged commit 464599f into dotnet:net11.0 Apr 30, 2026
198 of 216 checks passed

github-actions Bot added this to the .NET 11.0-preview4 milestone Apr 30, 2026

This was referenced May 1, 2026

[repo-status] .NET MAUI Daily Status - May 1, 2026 🌟 #35273

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[repo-status] .NET MAUI Daily Status - May 2, 2026 🌟 #35283

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github-actions Bot locked and limited conversation to collaborators May 31, 2026

PureWeen added the area-infrastructure CI, Maestro / Coherency, upstream dependencies/versions label Jun 10, 2026

PureWeen modified the milestones: .NET 11.0-preview4, .NET 11.0-preview5 Jun 10, 2026

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Pull request overview

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PureWeen commented Mar 24, 2026

Shell MenuItem Trimming Regression Analysis

Root Cause

Evidence from ADO Test Attachments (Build 1344675)

Failure Pattern

Suspected Trimmed Code Paths

Recommendation

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