0.9.0/0.9.1 don't build with Swift 5.0.x

[kengruven]

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What did you do?

The Cartfile of my project used to have the line:

github "iwasrobbed/Down" == 0.8.6

I want to try out a feature that's in the 0.9.x series, and I see in the README that 0.9.2+ is for Swift 5.1 (which I don't have), so I changed this line to:

github "iwasrobbed/Down" == 0.9.1

and ran:

carthage update --no-use-binaries --platform Mac Down

What did you expect to happen?

I expected version 0.9.1 to be built, and to appear in Carthage/Build/Mac/Down.framework.

What happened instead?

I got a compilation error:

.../Carthage/Checkouts/Down/Source/AST/Styling/Stylers/DownStyler.swift:38:71: error: type of expression is ambiguous without more context
    private var listPrefixAttributes: [NSAttributedString.Key : Any] {[
                                                                      ^

Looking at the code, this appears to be using a new Swift 5.1 language feature, even though it was added to Down in the 5.0-compatible era (0.9.0 / 0.9.1).

How hard would it be to add one word (return) here?

[kengruven]

I forked and branched (from tag "v0.9.1") with 2 small changes, and this builds with Swift 5.0.1 again:

master...kengruven:swift50

[iwasrobbed]

Hi @kengruven 👋 You're welcome to maintain your fork, but I'd rather not backport changes to prior Swift versions. It's a rabbit hole that only benefits a few people versus the maintainers having to keep a mental model of all these extra changes

[kengruven]

That's fair. Can we at least update the README?

[iwasrobbed]

@kengruven Done here 296ad54

Thanks for pointing it out