Bump min OS versions in .NET 9

[rolfbjarne]

We might have to bump min OS versions in .NET 9.

dotnet/runtime is bumping to iOS 12.2/tvOS 12.2: dotnet/runtime#91736, which might be a good choice since that's when iOS/tvOS started shipping Swift libraries (our current min is iOS/tvOS 11.0)

FWIW there's nothing filed in dotnet/runtime for macOS yet that I could find (our current min is macOS 10.15)

---

Versions were bumped to:

• iOS 12.2
• tvOS 12.2
• macOS 12.0
• Mac Catalyst 15.0

[akoeplinger]

The current min for macOS in dotnet/runtime is 10.15 too and there are no immediate plans to bump that. Unless you're aware of some good reason to do it?

[rolfbjarne]

The current min for macOS in dotnet/runtime is 10.15 too and there are no immediate plans to bump that. Unless you're aware of some good reason to do it?

The only reason I can think of is that we don't have bots to run tests on 10.15, so we're not really verifying that it works (earliest OS version we have is macOS 11.5).

[rolfbjarne]

One point towards bumping to iOS 12 and tvOS 12 is that Xcode 15 doesn't support deploying to an iOS 11 device.

From Xcode 15's release notes:

"The Xcode 15 release supports on-device debugging in iOS 12 and later, tvOS 12 and later, and watchOS 4 and later."

[dalexsoto]

I agree with the idea that 12.2 and company (that has swift provided by the OS) would be a great new default for us.

[UInt2048]

@rolfbjarne Wonder if it needs to be done sooner for the same reasons as #6213

[rolfbjarne]

@rolfbjarne Wonder if it needs to be done sooner for the same reasons as #6213

Xcode 15 (and probably 16) continues to support building for iOS 11 from the command line, even if the iDE doesn't support deploying to such devices.

[rolfbjarne]

It seems dotnet/runtime is bumping to macOS 12.0 (and thus Mac Catalyst 15.0) according to the docs here: https://github.com/dotnet/core/blob/main/release-notes/9.0/supported-os.md

Although I haven't found any issues/pull requests/discussions referring to this.

[akoeplinger]

Most of that discussion happened in dotnet/core#9038.
Basically the stance is that we'll only "support" what we test on, so this was also retroactively bumped to macOS 12.0 for .NET8 in the docs.

Of course this doesn't mean that the -mmacosx-version-min was changed in 8.0 (i.e. preventing earlier versions from running the binary) but I think we'd want to do that for 9.0.

[rolfbjarne]

@dalexsoto any particular reason we shouldn't bump to macOS 12.0 / Mac Catalyst 15.0 already?

[dalexsoto]

@dalexsoto any particular reason we shouldn't bump to macOS 12.0 / Mac Catalyst 15.0 already?

Not from me, I'll ask around but I do not see problem doing this.

[dalexsoto]

@rolfbjarne no one raised a flag so I would say let's do it!

[rolfbjarne]

Completed in f749cb3.