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 · 2026-03-31T09:27:00Z

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

azure-pipelines · 2026-03-31T09:27:19Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-03-31T16:16:26Z

/rebase

need to rerun with latest bits

PureWeen · 2026-03-31T17:03:14Z

/azp run

azure-pipelines · 2026-03-31T17:04:43Z

Azure Pipelines successfully started running 3 pipeline(s).

…/remove-istrimmable-false

kotlarmilos · 2026-04-01T13:56:41Z

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

azure-pipelines · 2026-04-01T13:57:08Z

Azure Pipelines successfully started running 2 pipeline(s).

PureWeen · 2026-04-02T15:04:49Z

Trimming Regression: `DragGestureRecognizer` constructor trimmed

The Android Mono and iOS Mono device test runs are crashing with MissingMethodException — this is PR-specific (these jobs pass on every net11.0 baseline build).

Crash from Helix logcat (Android Mono, build 1362029, job e7834259):

E AndroidRuntime: android.runtime.JavaProxyThrowable: [System.MissingMethodException]: 
    Activator_CannotCreateInstance, Microsoft.Maui.Controls.DragGestureRecognizer, Arg_NoDefCTorWithoutTypeName
    at System.RuntimeType+ActivatorCache..ctor + 0x99(Unknown Source)
    at System.RuntimeType+ActivatorCache.Create + 0x0(Unknown Source)

The trimmer is removing the default (parameterless) constructor of DragGestureRecognizer, which is needed by Activator.CreateInstance at runtime. This is the same class of issue as the Shell MenuShellItem fix — code paths reached via reflection/activation that the trimmer cannot statically trace.

iOS Mono shows the same APP_CRASH (exit code 80) pattern — app dies before producing any test results.

Evidence this is PR-specific:

Build	Android Mono	iOS Mono
net11.0 build 1363873	✅	✅
net11.0 build 1360789	✅	✅
net11.0 build 1360076	✅	✅
net11.0 build 1358994	✅	✅
net11.0 build 1357881	✅	✅
PR #34573 build 1362029	❌ crash	❌ crash

Likely needs [DynamicDependency] annotations on DragGestureRecognizer (and possibly other gesture recognizer types that are activated via reflection).

…cognizer class

kotlarmilos · 2026-04-07T10:33:49Z

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

azure-pipelines · 2026-04-07T10:34:05Z

Azure Pipelines successfully started running 2 pipeline(s).

…trimming - Cell.cs: Preserve Cell subtype constructors (TextCell, EntryCell, ImageCell, SwitchCell, ViewCell) - ViewExtensions.cs: Preserve XAML markup extension constructors for runtime XAML parsing - MemoryTests.cs: Add DynamicallyAccessedMembers on Type params for GestureDoesNotLeak, CellsDoNotLeak, CollectionViewHeaderFooterDoesntLeak - ControlsViewTypesTestCases.cs: Add DynamicDependency for all view types used via ClassData - AccessibilityTests.cs: Add DynamicDependency for all control types in AllControlsTestCase Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

kotlarmilos · 2026-04-08T09:39:04Z

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

azure-pipelines · 2026-04-08T09:39:20Z

Azure Pipelines successfully started running 2 pipeline(s).

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

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

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

32ae3cd

PureWeen previously approved these changes Mar 31, 2026

View reviewed changes

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

0fbe3c4

…/remove-istrimmable-false

build-analysis bot mentioned this pull request Apr 1, 2026

Known Test Repository Issue Sometimes Misses Test Failures dotnet/dnceng#6411

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PureWeen previously approved these changes Apr 2, 2026

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rolfbjarne previously approved these changes Apr 3, 2026

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Add DynamicDependency attributes for gesture recognizers in GestureRe…

ea09a18

…cognizer class

kotlarmilos dismissed stale reviews from rolfbjarne and PureWeen via ea09a18 April 7, 2026 10:24

build-analysis bot mentioned this pull request Apr 7, 2026

File upload failed even after retry dotnet/dnceng#1916

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Pull request overview

Reviewed changes

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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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PureWeen commented Apr 2, 2026

Trimming Regression: DragGestureRecognizer constructor trimmed

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Trimming Regression: `DragGestureRecognizer` constructor trimmed