Xamarin-macios: Resources are always considered as 'newer than output'

[alanmcgovern]

The step for me is to build any ios project with resources. If you then build it a second time it complains that the input file is newer than the output file for all resources, so we copy them all instead of doing a no-op.

I uploaded a 200mb log file here: https://xamarinhq.slack.com/files/U03CFBR1A/FA4T824L8/output

My repro project was the ios designer's MTDesigner.sln. In this project the issue shows up everywhewre, but you can look for FillTexture.png as one example when searching the logs

[alanmcgovern]

Running stat from a terminal:

stat -f "%m %N" bin/NoDist/Tests/MonoTouchDesignerServerTests.app/FillTexture.png  tests/MonoTouch.Designer.Server.Tests/obj-monotouch/FillTexture.png
1523528229 tests/MonoTouch.Designer.Server.Tests/obj-monotouch/FillTexture.png
1523528229 bin/NoDist/Tests/MonoTouchDesignerServerTests.app/FillTexture.png

Checking it via C#

csharp> new System.IO.FileInfo ("tests/MonoTouch.Designer.Server.Tests/obj-monotouch/FillTexture.png").LastWriteTimeUtc.Ticks
636591250290764649

csharp> new System.IO.FileInfo ("bin/NoDist/Tests/MonoTouchDesignerServerTests.app/FillTexture.png").LastWriteTimeUtc.Ticks
636591250290000000

As you can see the output is older than the input.

[alanmcgovern]

mono --version
Mono JIT compiler version 5.14.0.12 (2018-04/7af9ad8cdb6 Fri Apr  6 10:50:49 EDT 2018)

on MacOS 10.13.4

[filipnavara]

I think this is related to https://github.com/xamarin/xamarin-macios/issues/3584. In fact, it also triggers rebuilds of dependent projects, which could end up being quite costly.

[filipnavara]

Also, there was another issue for Mono cutting the resolution of file times. I thought it was already resolved in 2018-04 though. https://github.com/mono/mono/issues/7646

[spouliot]

I'm pretty sure @filipnavara nailed it with the mono issue since the numbers above shows the value is truncated.

@lewurm do you know if the version that @alanmcgovern mentioned above (5.14.0.12) has the fix (or not) ?

[lewurm]

5.14.0.12 contains the fix, and I agree, the symptoms look the same.

@alanmcgovern do you know _how_ bin/NoDist/Tests/MonoTouchDesignerServerTests.app/FillTexture.png is copied? potentially MONO_LOG_LEVEL=debug MONO_LOG_MASK="io-layer-file" could help to track it down.

[alanmcgovern]

It’s copied with File.Copy if that’s any use. I can dig in more if you need more than that

[lewurm]

that looks like it would be the cause of the issue:

csharp> new System.IO.FileInfo ("hello").LastWriteTimeUtc.Ticks
636592027029502131
csharp> System.IO.File.Copy ("hello", "hello_copy")
csharp> new System.IO.FileInfo ("hello_copy").LastWriteTimeUtc.Ticks
636592027020000000

gonna look into it

[alanmcgovern]

Using Mono JIT compiler version 5.14.0.40 (2018-04/d835b7d55f0 Sun Apr 15 14:05:04 EDT 2018) the issue is still there:

csharp> new System.IO.FileInfo ("obj/Debug/build.props").LastWriteTimeUtc.Ticks
636596459657450000
csharp> new System.IO.FileInfo ("obj/Debug/resourcepaths.cache").LastWriteTimeUtc.Ticks
636596454888160000

stat -f "%m %N" obj/Debug/build.props obj/Debug/resourcepaths.cache                                                           
1524048315 obj/Debug/build.props
1524048316 obj/Debug/resourcepaths.cache

[lewurm]

follow-up fix potentially fixes the issue Alan is seeing https://github.com/mono/mono/pull/8293

we are waiting for the package so he can test it

[alanmcgovern]

This latest patch seems to have fixed the issues we were seeing!

LGTM!

Thanks!