Realm-dotnet: Realms.Exceptions.RealmFileAccessErrorException: Unable to open a realm at path

[dajbych]

Goals

Reliable realm database creation.

Expected Results

Realm instance.

Actual Results

_Realms.Exceptions.RealmFileAccessErrorException: 'Unable to open a realm at path 'C:\Users\Václav\AppData\Local\Packages\7539ef42-e9e8-4e55-8c45-547c7a6ee489_v1yjhd5ekz562\LocalCache\realmtest.realm.management': make_dir() failed: No such file or directory.'_

Steps to Reproduce

Simple project for bug reproduction: https://1drv.ms/u/s!AlFEHk1e5ZDCoL1NodRClQwLeQdO6A

Code Sample

class RealmEntity : RealmObject {
    [PrimaryKey]
    public long Id { get; set; }
}

readonly static RealmConfiguration config = new RealmConfiguration(Path.Combine(ApplicationData.Current.LocalCacheFolder.Path, "realmtest.realm")) {
    SchemaVersion = 1,
    ObjectClasses = new Type[] { typeof(RealmEntity) },
    ShouldDeleteIfMigrationNeeded = true
};

async void Page_Loaded(object sender, RoutedEventArgs e) {
    using (var realm = await Realm.GetInstanceAsync(config)) {
    }
}

Version of Realm and Tooling

• Client NuGet package version: 2.2.0
• Client OS & Version: Windows 10 version 1709 (build 16299.248)

Hint

I think (but I cannot be sure) that instance creation fails because of lack of UTF-8 support. The directory path contains non-ascii characters. I can reproduce this issue only on user accounts with non-ascii characters in the profile directory path.

[dajbych]

Still reproducible in version 3.0.0 of the client NuGet package.

[nirinchev]

You are correct - non-ascii characters in the path are not supported yet on Windows, sorry about that.

[dajbych]

Will it be fixed in the next version? What is expected release date of the next version?

[nirinchev]

We don't have a timeframe for when this will be addressed.

[juhasuni]

This is actually a very serious issue, since realm-dotnet cannot be reliably used with UWP apps that run sandboxed. It is very likely that user's profile folder contains non-ascii characters. It looks like the issue resides at realm-core's file.cpp where _mkdir function is used and _wmkdir should be used instead. I'm not experienced in C++, but I assume that it cannot be safely switched to use _wmkdir because the same core is compiled for multiple platforms.

[nirinchev]

Correct, we're aware of the problem and are working on finding a path forward. Unfortunately, I still can't provide you with a timeframe other than saying that there are people currently looking at it - if it turns out it's a simple fix, we may ship a fix with the next .NET version (which is planned for mid May). Otherwise, it may have to wait longer.

[AliGuemues]

Is there now any timeframe when this issue would fixed? We also want to use Realm in UWP-Project but we are not able because of the known issue.

[tipa]

Any updates to this?

[peterxme]

I think this has been fixed for Windows in realm-core #3293. @nirinchev can you confirm with us here that this Windows fix is part of the latest realm-dotnet release?

[nirinchev]

It is not part of the latest release unfortunately.

[tipa]

Would it be possible to push this as an update? I am getting a significant amount of crash reports because of this bug

[nirinchev]

Yes, I was hoping to do a point release this week.