Provide some guidance for the confusing "does not provide a dex boot
jar" message.
Test: n/a
Bug: 207778789
Change-Id: I720471568e0b57636fb979c93a689895e9beaa02
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 75083e8..c599c4d 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -506,8 +506,18 @@
dst := dstBootJarsByModule[name]
if src == nil {
+ // A dex boot jar should be provided by the source java module. It needs to be installable or
+ // have compile_dex=true - cf. assignments to java.Module.dexJarFile.
+ //
+ // However, the source java module may be either replaced or overridden (using prefer:true) by
+ // a prebuilt java module with the same name. In that case the dex boot jar needs to be
+ // provided by the corresponding prebuilt APEX module. That APEX is the one that refers
+ // through a exported_(boot|systemserver)classpath_fragments property to a
+ // prebuilt_(boot|systemserver)classpath_fragment module, which in turn lists the prebuilt
+ // java module in the contents property. If that chain is broken then this dependency will
+ // fail.
if !ctx.Config().AllowMissingDependencies() {
- ctx.ModuleErrorf("module %s does not provide a dex boot jar", name)
+ ctx.ModuleErrorf("module %s does not provide a dex boot jar (see comment next to this message in Soong for details)", name)
} else {
ctx.AddMissingDependencies([]string{name})
}