[wasm] Build doesn't rebuild when certain properties change

[vargaz]

Description

Changing certain msbuild properties doesn't cause the app to be rebuilt.

Reproduction Steps

In src/mono/sample/wasm/console-v8:

1. WasmBuildNative time make MSBUILD_ARGS="/p:WasmBuildNative=true" time make MSBUILD_ARGS="/p:WasmBuildNative=false" -> the second one doesn't rebuild. It should be using dotnet.*wasm from the runtime pack.
2. WasmNativeStrip time make MSBUILD_ARGS="/p:WasmBuildNative=true /p:WasmNativeStrip=false" time make MSBUILD_ARGS="/p:WasmBuildNative=true /p:WasmNativeStrip=true" -> the second one doesn't rebuild
3. WasmEnableWebcil time make MSBUILD_ARGS="" time make MSBUILD_ARGS="/p:WasmEnableWebcil=false" -> the second one doesn't rebuild.

   Expected behavior

Rebuilds.

Actual behavior

.

Regression?

No response

Known Workarounds

No response

Configuration

dotnet/runtime master

Other information

No response

[vargaz]

@radical

[ghost]

Tagging subscribers to 'arch-wasm': @lewing See info in area-owners.md if you want to be subscribed.

Issue Details

---

### Description Changing certain msbuild properties doesn't cause the app to be rebuilt. ### Reproduction Steps In src/mono/sample/wasm/console-v8: 1. WasmBuildNative ```time make MSBUILD_ARGS="/p:WasmBuildNative=false" time make MSBUILD_ARGS="/p:WasmBuildNative=true" ``` -> the second one doesn't rebuild 2. WasmNativeStrip ```time make MSBUILD_ARGS="/p:WasmBuildNative=true /p:WasmNativeStrip=false" time make MSBUILD_ARGS="/p:WasmBuildNative=true /p:WasmNativeStrip=true" ``` -> the second one doesn't rebuild ### Expected behavior Rebuilds. ### Actual behavior . ### Regression? _No response_ ### Known Workarounds _No response_ ### Configuration dotnet/runtime master ### Other information _No response_

Author:	vargaz
Assignees:	radical
Labels:	`arch-wasm`, `untriaged`, `area-Build-mono`
Milestone:	-

[ilonatommy]

It should be using dotnet.*wasm from the runtime pack.

• p:WasmBuildNative=true: Copying file from "/workspaces/runtime/artifacts/bin/microsoft.netcore.app.runtime.browser-wasm/Release/runtimes/browser-wasm/native/dotnet.native.wasm" to "/workspaces/runtime/src/mono/sample/wasm/console-v8/bin/browser-wasm/dotnet.native.wasm".
• WasmBuildNative=false: Did not copy from file "/workspaces/runtime/artifacts/bin/microsoft.netcore.app.runtime.browser-wasm/Release/runtimes/browser-wasm/native/dotnet.native.wasm" to file "bin/browser-wasm/dotnet.native.wasm" because the "SkipUnchangedFiles" parameter was set to "true" in the project and the files' sizes and timestamps match.

Judging by the message, it's an expected behavior. However, when we pass:

• WasmBuildNative=false SkipUnchangedFiles=false: Did not copy from file "/workspaces/runtime/artifacts/bin/microsoft.netcore.app.runtime.browser-wasm/Release/runtimes/browser-wasm/native/dotnet.native.wasm" to file "bin/browser-wasm/dotnet.native.wasm" because the "SkipUnchangedFiles" parameter was set to "true" in the project and the files' sizes and timestamps match.

We should have a way of passing SkipUnchangedFiles to the target that copies to AppBundle.

[radical]

We should have a way of passing SkipUnchangedFiles to the target that copies to AppBundle.

That's an implementation detail. For this issue you will probably need to track some important properties for every build, so save their values during a build. And when a subsequent one is done then you can compare whether any of the important properties changed, and if so trigger a native rebuild.