XcodeConfigInfo.macosMinimumOsVersion is incorrectly set for host configuration

[brentleyjones]

Description of the problem / feature request:

When building a target with the host configuration, the macosMinimumOsVersion is being set to the SDK version instead of what is set for --macos_minimum_os. The relevant lines are:

bazel/src/main/java/com/google/devtools/build/lib/rules/apple/XcodeConfig.java

Lines 149 to 152 in 24c980b

	DottedVersion macosMinimumOsVersion =
	(appleOptions.macosMinimumOs != null)
	? DottedVersion.maybeUnwrap(appleOptions.macosMinimumOs)
	: macosSdkVersion;

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Build a genrule that has a swift_binary tool, with --macos_minimum_os lower than the SDK version (say 10.15 when using Xcode 12.4.0, which has its SDK version at 11.1). The tool will have an incorrect -target (x86_64-apple-macosx11.1 for the example given).

What operating system are you running Bazel on?

macOS 11.2.1

What's the output of bazel info release?

release 4.0.0

Have you found anything relevant by searching the web?

Nothing.

[keith]

I think the issue is that the minimum version isn't set for the host configuration here?

bazel/src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java

Lines 456 to 468 in 660f5b2

	// Set options needed in the host configuration.
	host.xcodeVersionConfig = xcodeVersionConfig;
	host.xcodeVersion = xcodeVersion;
	host.iosSdkVersion = iosSdkVersion;
	host.watchOsSdkVersion = watchOsSdkVersion;
	host.tvOsSdkVersion = tvOsSdkVersion;
	host.macOsSdkVersion = macOsSdkVersion;
	host.appleBitcodeMode = appleBitcodeMode;
	// The host apple platform type will always be MACOS, as no other apple platform type can
	// currently execute build actions. If that were the case, a host_apple_platform_type flag might
	// be needed.
	host.applePlatformType = PlatformType.MACOS;
	host.configurationDistinguisher = ConfigurationDistinguisher.UNKNOWN;

But maybe that's intentional

[brentleyjones]

If it's intentional, could we get a --host_minimum_os flag? Hopefully it's not intentional though 😄.

[brentleyjones]

I just realized this might be semi-intentional, since we only need to support a minimum OS of the host, not any lower. In my example though, by using Xcode 12.4, the macOsSdkVersion is 11.1, while my OS version (in a previous test) was 10.15. Ideally we wouldn't try targeting an OS version higher than the current one?

[keith]

minimum OS of the host

To ensure caching across developers even this isn't particularly true is it? I get that you won't back deploy the binary directly, but it could result in a different output

[brentleyjones]

To ensure caching across developers even this isn't particularly true is it? I get that you won't back deploy the binary directly, but it could result in a different output

True. So then I would want to set a minimum OS version that might be lower than the OS version of the host.

[keith]

#13001

[aiuto]

cc @susinmotion Any thoughts on #13001?

[susinmotion]

It's in good hands with trybka and allevato!