I'm trying to run downloaded from app, try to open in Xcode and have an error:
" Showing Recent Messages
:-1: SWIFT_VERSION '3.0' is unsupported, supported versions are: 4.0, 4.2, 5.0. (in target 'SimpleWeather')"
Select the target 'SimpleWeather' in the project and change language version Target->build setting -> Swift compiler language -> select 5, 4.2 etc
It seems that the app might have an old Swift version code like Swift 3.0 in your case. In the release of Xcode version 10.2 has launched Swift 5.0 version. Xcode 10.2 does not support compiler for Swift 3.0 version. You can change compiler from Build Settings -> Swift Compiler - Language -> Swift Language Version -> Change it to Swift 5
. If your code is compatible with that language version then it will run the code without error.
However, the Swift 3 compatibility mode will not be supported in the Swift 5 compiler. Swift 4.2 is the last release of Swift to support Swift 3 mode. There are important changes to both the surface of the language and the interior of its implementation in the releases following Swift 3 that will be the basis of future (and lasting) source and binary stability.
Refer below link for more details. https://developer.apple.com/documentation/xcode_release_notes/xcode_10_2_release_notes/swift_5_release_notes_for_xcode_10_2
If you really wish to run the app which has older Swift version code than you must have to use an older version of Xcode. You can use Xcode version 10.1, it's compiler having support for Swift 3.0 version.
Another alternative way is to migrate your old Swift code to the new version of the Swift version. You can migrate you Swift 3.0 to Swift 4.0 in Xcode 10.1 version.
For migration guide refer to this https://swift.org/migration-guide-swift4/
I came across this issue while developing a Cocoapod. I had an old .swift-version
file in my repo that specified Swift 3.0.
Running pod lib lint --verbose
led me to this helpful response:
Please remove the
.swift-version
file which is now deprecated and only use theswift_version
attribute within your podspec.
I deleted the file and added spec.swift_version = '5.0'
to my podspec file to fix the problem.
I followed the instructions on this page and the error didn't resolve. Finally, went into
$ vim MyProject.xcodeproj/project.pbxproj
and found two instances where
SWIFT_VERSION = 3.0;
was still being referenced. I changed those to 5.0 and the error was gone. Not sure why those two were still there.
来源:https://stackoverflow.com/questions/55366024/how-to-fix-swift-version-3-0-is-unsupported-supported-versions-are-4-0-4-2