Expand comment about using a merge api base
A bit more context for the next person looking into improving this
check (it's not straightforward).
Test: No
Change-Id: Ie389bc10dcc307a996dc3a7fad55405fe12a09b9
diff --git a/api/Android.bp b/api/Android.bp
index 2c6cade..5b65e91 100644
--- a/api/Android.bp
+++ b/api/Android.bp
@@ -179,8 +179,10 @@
cmd: metalava_cmd +
"--check-compatibility:api:released $(location :android.api.module-lib.latest) " +
// Note: having "public" be the base of module-lib is not perfect -- it should
- // ideally be a merged public+system), but this will help when migrating from
- // MODULE_LIBS -> public.
+ // ideally be a merged public+system (which metalava is not currently able to generate).
+ // This "base" will help when migrating from MODULE_LIBS -> public, but not when
+ // migrating from MODULE_LIBS -> system (where it needs to instead be listed as
+ // an incompatibility).
"--check-compatibility:base $(location :frameworks-base-api-current.txt) " +
"--baseline:compatibility:released $(location :android-incompatibilities.api.module-lib.latest) " +
"--update-baseline:compatibility:released $(genDir)/updated-baseline.txt " +