The recipe in generate-link-opt-data is currently hiding stderr output from the java process unless LOG=debug is set. It seems like in normal operation, the tool does not print anything on stderr, so we should just let that through to the console instead of trying to hinder it.

I just debugged a build error in that recipe and the error was hidden until I ran with LOG=debug. With the below patch, the error was visible, but unfortunately, some bogus log output from the Hello java program gets through instead.

diff -r 2bea53d7a27b make/GenerateLinkOptData.gmk
--- a/make/GenerateLinkOptData.gmk
+++ b/make/GenerateLinkOptData.gmk
@@ -65,7 +65,7 @@
            -Djava.lang.invoke.MethodHandle.TRACE_RESOLVE=true \
            -cp $(SUPPORT_OUTPUTDIR)/classlist.jar \
            build.tools.classlist.HelloClasslist \
- $(LOG_DEBUG) 2>&1 > $(JLI_TRACE_FILE)
+ > $(JLI_TRACE_FILE)
        $(GREP) -v HelloClasslist $@.raw > $@
 
 # The jli trace is created by the same recipe as classlist. By declaring these