nom run dev 报错

[vecharm]

events.js:165
throw er; // Unhandled 'error' event
^

Error: listen EADDRINUSE 127.0.0.1:8080
at Server.setupListenHandle [as _listen2] (net.js:1346:14)
at listenInCluster (net.js:1387:12)
at GetAddrInfoReqWrap.doListen [as callback] (net.js:1502:7)
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:72:10)
Emitted 'error' event at:
at emitErrorNT (net.js:1366:8)
at process._tickCallback (internal/process/next_tick.js:178:19)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! mpvue-zanui@1.0.1 dev: node build/dev-server.js
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the mpvue-zanui@1.0.1 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /Users/wuweichang/.npm/_logs/2018-04-23T13_32_53_372Z-debug.log

[armyja]

请问执行 npm run dev 之前做了哪些操作呢？