I get this trouble for tows days almost crazy ...

oker@jujungdeMacBook-Pro demo01 % gem list execjs
*** LOCAL GEMS ***
execjs (2.8.1, 2.7.0)
====================================================
oker@jujungdeMacBook-Pro demo01 % ruby -rexecjs -e 'puts ExecJS.runtime; puts ExecJS::VERSION; puts ExecJS.runtime.name'
#<ExecJS::MiniRacerRuntime:0x00007fef048ccf08>
2.8.1
mini_racer (V8)
===========================================
but i can user 'zat server' or other commands. only validate,pacakge,update this three commands have trouble. please help me , thank you。