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

[pswaminathan]

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

[sgowroji]

Hello @pswaminathan, Could you please share the right URL links for the given links https://github.com/pswaminathan/barest-kotlin/pull/2, 58e6843, 56e4806. These pages are not available. Thanks!

[pswaminathan]

@sgowroji whoops, I made the repository private by accident. I've made it public now so those links should work!

[ahumesky]

Hmm, I wasn't able to reproduce this:

barest-kotlin$ cat android/app/BUILD.bazel 
load("@io_bazel_rules_kotlin//kotlin:android.bzl", "kt_android_library")

kt_android_library(
    name = "lib",
    srcs = ["MainActivity.kt"],
    visibility = ["//visibility:private"],
    deps = [
    ],
)

android_binary(
    name = "app",
    deps = [":lib"],
    manifest = "AndroidManifest.xml",
    dex_shards = 1,
)

barest-kotlin$ ls ~/android-sdk/build-tools/
33.0.0

barest-kotlin$ bazel version
Starting local Bazel server and connecting to it...
Build label: 6.0.0-pre.20220818.1
Build target: bazel-out/k8-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Wed Aug 24 17:12:26 2022 (1661361146)
Build timestamp: 1661361146
Build timestamp as int: 1661361146

barest-kotlin$ bazel clean --expunge
INFO: Starting clean (this may take a while). Consider using --async if the clean takes more than several minutes.

barest-kotlin$ bazel build android/app
Starting local Bazel server and connecting to it...
INFO: Analyzed target //android/app:app (64 packages loaded, 1107 targets configured).
INFO: Found 1 target...
Target //android/app:app up-to-date:
  bazel-bin/android/app/app_deploy.jar
  bazel-bin/android/app/app_unsigned.apk
  bazel-bin/android/app/app.apk
INFO: Elapsed time: 23.307s, Critical Path: 10.05s
INFO: 71 processes: 35 internal, 24 linux-sandbox, 12 worker.
INFO: Build completed successfully, 71 total actions

@pswaminathan could you confirm that this still fails? or perhaps I missed something in the repro?

[sgowroji]

Hello @pswaminathan, Could you please check the above comment and reply. Thanks

[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.

[sgowroji]

Thank you for the reply. We will be waiting to hear it from you.

[ahumesky]

let us know if this is still an issue