[BUG] Dependency chain issues for .net 6

[nick-randal]

Describe the bug

Dependency chain issues

To Reproduce

using a .net 6.0 project upgrade to ZiggyCreatures.FusionCache 2.1.0

this package shows dependencies as:
.NET 6.0        
Microsoft.Extensions.Caching.Memory ≥ 9.0.0        
System.Collections.Immutable ≥ 9.0.0

Compile

Warning : System.Collections.Immutable 9.0.0 doesn't support net6.0 and has not been tested with it.

Expected behavior

Should not have unsupported dependencies.

Versions

• FusionCache version 2.1.0
• .NET version 6.0
• OS version MacOs 15.3.1

[jodydonetti]

Hi @nick-randal

Expected behavior

Should not have unsupported dependencies.

I don't know exactly what you mean with "unsupported": maybe you mean "unsupported at all by Microsoft" or maybe you mean "unsupported with .NET 6", like "incompatible".
I'd like to clarify a couple of things so we are on the same page (and please tell me if I'm wrong).

Core v9 packages are totally compatible with .NET 6, so much so that they are even compatible with the very old .NET Framework v4.X, see here:

So, core packages v9 are in fact supported by Microsoft since they are considered part of .NET 9 (which has been out since last November, and is supported by Microsoft): it's just that they are part of the .NET 9 wave, which in turn means STS instead of LTS.

Instead .NET 6 itself, which is what you are using, is really not supported anymore by Microsoft, since support ended Novembe 2024 (see here):

Now, FusionCache uses multi-targeting to reduce the number of explicitly declared dependencies, since with every new version .NET contains more core packages as implicit dependencies.

If your problem is that v9 packages are STS, you can read here for a recent (long) discussion about this topic: long story short here's the solution. It's v2.0.1 which does not include the HybridCache support (since it requires v9 core packages) and targets only LTS packages (so, v8 core packages).

If instead you meant something else please let me know.

Hope this helps.

[nick-randal]

The message is coming from the compiler. I, originally, only grabbed the first part of it but I included the entire message below if that helps.

What I mean by unsupported is that FusionCache 2.1.0 indicates it works with .net 6.0 but it requires version 9 of
Microsoft.Extensions.Caching.Memory and System.Collections.Immutable. You are then, in turn, required to upgrade those packages but that forces a warning that indicates those packages are not supported on .net 6.0. If you are required to operate under Warnings as Errors, this puts you in a breaking situation.

Unless you see another alternative, that leaves 1 of 2 options:

• Don't force version 9 of those libraries, or
• Drop .net 6 as a supported framework for FusionCache.

Starting from here

    <PackageVersion Include="ZiggyCreatures.FusionCache" Version="2.0.1" />
    <PackageVersion Include="ZiggyCreatures.FusionCache.Serialization.NewtonsoftJson" Version="2.0.1" />

No issues, this works fine with .net 6.0.

Change to ... and recompile

    <PackageVersion Include="ZiggyCreatures.FusionCache" Version="2.1.0" />
    <PackageVersion Include="ZiggyCreatures.FusionCache.Serialization.NewtonsoftJson" Version="2.1.0" />

Warning : Microsoft.Extensions.Caching.Memory 9.0.2 doesn't support net6.0 and has not been tested with it. Consider upgrading your TargetFramework to net8.0 or later. You may also set true in the project file to ignore this warning and attempt to run in this unsupported configuration at your own risk.

While it is helpful to some that the library is supported on .net framework it does not help is someone is targetting .net 6. As your screenshot shows, .net 6 is not listed as a supported framework. In addition they dropped .net Standard 2.1 which would have also covered .net 6.

[jodydonetti]

Hi @nick-randal

The message is coming from the compiler.

Ah! Never saw that, thanks for pointing that out.

What I mean by unsupported is that FusionCache 2.1.0 indicates it works with .net 6.0 but it requires version 9 of Microsoft.Extensions.Caching.Memory and System.Collections.Immutable. You are then, in turn, required to upgrade those packages but that forces a warning that indicates those packages are not supported on .net 6.0. If you are required to operate under Warnings as Errors, this puts you in a breaking situation.

Well, kind of: I get the part "indicates it works with .net 6.0" but in reality the intent was "for .NET 6 these are the explicit dependencies". But again, I now see your point clearly, and I wasn't aware of this detail.

Here's where it gets interesting though: I can remove the explicit .NET 6 targeting, and by leaving the .NET Standard 2.0 one it will still be compatible with .NET 6 (since .NET 6 is a compatible implementation of .NET Standard 2.0).

So... what would happend there? Would there still be warnings? I don't know, I'll try to take a look at this.

On top of this, I may simply drop .NET tfms that are officially not supported anymore (like .NET 3.1 and .NET 6, for example).

Unless you see another alternative, that leaves 1 of 2 options:

• Don't force version 9 of those libraries

Exactly, this is what I've done with the v2.0.1 release.

• Drop .net 6 as a supported framework for FusionCache.

Exactly, the thing I mentione above.

Starting from here

<PackageVersion Include="ZiggyCreatures.FusionCache" Version="2.0.1" />
<PackageVersion Include="ZiggyCreatures.FusionCache.Serialization.NewtonsoftJson" Version="2.0.1" />

No issues, this works fine with .net 6.0.

Good! Are you good with this solution?

Also, since the support theme seems to be important to you, I'd like to ask: are you planning to upgrade to a supported version of .NET anyway (eg: .NET 8)?

While it is helpful to some that the library is supported on .net framework it does not help is someone is targetting .net 6. As your screenshot shows, .net 6 is not listed as a supported framework.

Again, kinda: by having .NET Standard 2.0, .NET 6 is implicitly compatible anyway.

In fact if you switch to the "Frameworks" tab you can see this:

In addition they dropped .net Standard 2.1 which would have also covered .net 6.

I don't think so, .NET 6 is already covered anyway: they did not explicitly include .NET Standard 2.1 because it's not needed, since .NET Standard 2.0 is more than enough for that package. And since .NET Standard 2.1 is .NET Standard 2.0 + some things (things which are not needed in that package), everything compatible with .NET Standard 2.0 is also covered (like .NET 6).

Thoughts?

[nick-randal]

Since the MS packages have dropped .net 6 explicitly for version 9 and that version is required going forward with FusionCache, I would suggest dropping .net 6 as a TFM.

The reason this came up for me is that I am maintaining internal company packages and some of those use FusionCache. These packages are also multi targeting 6/8 to support developers while they work through migrating from 6 to 8. We skip STS versions.

[jodydonetti]

Since the MS packages have dropped .net 6 explicitly for version 9 and that version is required going forward with FusionCache, I would suggest dropping .net 6 as a TFM.

Yeah, it kinda makes sense.
I looked into the dependencies for the previous versions and basicaly it's like this:

• v8 packages contain an explicit .NET 6 target, since when .NET 8 came out .NET 6 was still supported
• v9 packges removed the explicit .NET 6 target, since when .NET 9 came out .NET 6 was not supported anymore

Based on these "rules", I should probably simply remove the direct .NET 6 target (and .NET 3.1 too), falling back to .NET Standard 2.0 wich will cover both anyway, but not in a direct fashion.

The reason this came up for me is that I am maintaining internal company packages and some of those use FusionCache.

I hope FusionCache is being helpful, and if you or one of your colleagues have some time please see here 🙂.

It's the only way for me to know how FusionCache is being used.

Thanks!

[nick-randal]

Submitted and yes very pleased so far. This has the potential to be a mainstay within our applications.

[jodydonetti]

Hi @nick-randal , I just created #425 to outline the changes I'm doing, and it would be great to have your opinion on that.

Thanks.

[jodydonetti]

Hi all, v2.2.0-preview-1 is out 🥳