Bazel tries to use dx instead of d8 if using default dex_shards with Android Build Tools >=31

Description of the bug:

Android build tools >=31 removed dx in favor of d8. However, when building an android_binary, Bazel still attempts to use dx if dex_shards is 1 (as the unset default or explicitly set to 1). Setting a non-standard dex_shards makes this go away, but Bazel shouldn’t be trying to use dx regardless.

This behavior persists even if using flags to explicitly use d8:

build --define=android_dexmerger_tool=d8_dexmerger
build --define=android_incremental_dexing_tool=d8_dexbuilder
build --define=android_standalone_dexing_tool=d8_compat_dx

What’s the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Example project at https://github.com/pswaminathan/barest-kotlin/pull/2.

58e6843 updates the build tools to a version without dx. This commit does not build. The error message I receive is:

ERROR: /private/var/tmp/_bazel_p/afc4c6dd0737eebec931aeb282f26bc9/external/androidsdk/BUILD.bazel:13:25: Extracting interface @androidsdk//:dx_jar_import [for tool] failed: missing input file '@androidsdk//:build-tools/31.0.0/lib/dx.jar'

56e4806 fixes it simply by adding dex_shards = 2.

Which operating system are you running Bazel on?

macOS Monterey (12.5.1)

What is the output of bazel info release?

release 6.0.0-pre.20220818.1

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What’s the output of git remote get-url origin; git rev-parse master; git rev-parse HEAD ?

No response

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

No response

[pswaminathan]

Hmm, interesting, I’m not able to reproduce it now either. Maybe something was cached? Interestingly, one of our other team members was experiencing this as well. I’ll ask him to try reproducing again.

[ahumesky]

let us know if this is still an issue