android_build/core/tasks

dex_preopt_check

dex_preopt_check is a build-time check to make sure that all system server jars are dexpreopted. When the check fails, you will see the following error message:

FAILED:
build/make/core/tasks/dex_preopt_check.mk:13: warning:  Missing compilation artifacts. Dexpreopting is not working for some system server jars
Offending entries:

Possible causes are:

1. There is an APEX/SDK mismatch. (E.g., the APEX is built from source while the SDK is built from prebuilt.)

2. The systemserverclasspath_fragment is not added as systemserverclasspath_fragments of the corresponding apex module, or not added as exported_systemserverclasspath_fragments of the corresponding prebuilt_apex/apex_set module when building from prebuilt.

3. The expected version of the system server java library is not preferred. (E.g., the java_import module has prefer: false when building from prebuilt.)

4. Dexpreopting is disabled for the system server java library. This can be due to various reasons including but not limited to:

   • The java library has dex_preopt: { enabled: false } in the Android.bp file.

   • The java library is listed in DEXPREOPT_DISABLED_MODULES in a Makefile.

   • The java library is missing installable: true in the Android.bp file when building from source.

   • Sanitizer is enabled.

5. PRODUCT_SYSTEM_SERVER_JARS, PRODUCT_APEX_SYSTEM_SERVER_JARS, PRODUCT_STANDALONE_SYSTEM_SERVER_JARS, or PRODUCT_APEX_STANDALONE_SYSTEM_SERVER_JARS has an extra entry that is not needed by the product.