Help "No protocol compiler found" that gradlew reported

I am hitting an issue when running “./gradlew idea” or any argument . it always reports “No protocol compiler found”. I have installed protobuf compiler in /usr/local/bin. I am very puzzled where gradle is trying to locate the “protocol compiler” ? Any help will be appreciated. thanks!

$ ./gradlew tasks
:buildSrc:compileJava UP-TO-DATE
:buildSrc:compileGroovy UP-TO-DATE
:buildSrc:processResources UP-TO-DATE
:buildSrc:classes UP-TO-DATE
:buildSrc:jar UP-TO-DATE
:buildSrc:assemble UP-TO-DATE
:buildSrc:compileTestJava UP-TO-DATE
:buildSrc:compileTestGroovy UP-TO-DATE
:buildSrc:processTestResources UP-TO-DATE
:buildSrc:testClasses UP-TO-DATE
:buildSrc:test UP-TO-DATE
:buildSrc:check UP-TO-DATE
:buildSrc:build UP-TO-DATE
System Properties:
java.home=C:\Program Files\Java\jdk1.8.0_77\jre
java.version=1.8.0_77
os.name=Windows 10
user.dir=C:\Users\yangj15\ViprTest\storage
user.home=C:\Users\yangj15
Building Version: 3.3.0.0.103854.b825a38
Git Version: ECS-3.2.0.0-RC3-2431-gb825a38d7ad
Git Branch: feature-bplustree-with-mapping-table
Git Hash: b825a38d7ad31eaf521ca8cd4e259db86d06c701
System Properties:
java.home=C:\Program Files\Java\jdk1.8.0_77\jre
java.version=1.8.0_77
os.name=Windows 10
user.dir=C:\Users\yangj15\ViprTest\storage
user.home=C:\Users\yangj15
*** No protocol compiler found ***
*** No protocol compiler found ***
findbugs datasvc/blobsvc excludeFilter:

yangj15@CNENYANGJ15L1C MINGW64 ~/Test/
$ which protoc
/usr/local/bin/protoc

yangj15@CNENYANGJ15L1C MINGW64 ~/Test/
$ protoc --version
libprotoc 2.5.0

After Enabling stacktrace, I see:
07:31:46.675 [ERROR] [org.gradle.api.Project] *** No protocol compiler found ***