Remove -incremental when using -whole-module-optimization

[keith]

Passing both results in noisy remarks when building from the command line like:

remark: Incremental compilation has been disabled: it is not compatible with whole module optimization

https://forums.swift.org/t/incremental-compilation-has-been-disabled-it-is-not-compatible-with-whole-module-optimization/66092

[keith]

@swift-ci please test

[MaxDesiatov]

@swift-ci smoke test

[artemcm]

Thanks.

[keith]

hrm seems like this isn't a problem in the release branch https://github.com/apple/swift-package-manager/blob/release/5.9/Sources/Build/BuildDescription/SwiftTargetBuildDescription.swift#L543

[keith]

ah it looks like llbuild needs a similar change, I will submit PRs there

[keith]

swiftlang/swift-llbuild#884

[keith]

so at HEAD this change is enough but on 5.9 this change isn't needed and the llbuild change is enough. I submitted the llbuild change in both places either way

[neonichu]

Yah, we switched away from using llbuild's built-in Swift command in main

[doozMen]

When I run with swift 5.9 but in my package.swift I have 5.7 it still outputs remark: Incremental compilation has been disabled: it is not compatible with whole module optimization. Does this mean it is not fixed in 5.9?

[finagolfin]

Does this mean it is not fixed in 5.9?

It sounds like you're picking up an old Swift in your path somewhere. Try running with -v verbose mode and see which Swift compiler it's using. If you're sure it's 5.9 or later, let us know.

[kaishin]

It sounds like you're picking up an old Swift in your path somewhere. Try running with -v verbose mode and see which Swift compiler it's using. If you're sure it's 5.9 or later, let us know.

I am still seeing this with Swift 5.9.