less 写代码的时候 npm run build 出现样式编译错误 ？

[w3cui]

我在开发模式不出现错误 以但打包发布就报错，感觉是webpack build 配置有问题，求解决！
错误如下：
umi build

Build completed in 42.202s

ERROR Failed to compile with 1 errors 3:47:22 PM
error in ./src/pages/index/index.less

Module build failed (from ./node_modules/_mini-css-extract-plugin@0.7.0@mini-css-extract-plugin/dist/loader.js):
ModuleNotFoundError: Module not found: Error: Can't resolve 'images/bg.png' in 'D:\www\dtk_react_flow_www\wap\src\pages\index'
at factory.create (D:\www\dtk_react_flow_www\wap\node_modules_webpack@4.38.0@webpack\lib\Compilation.js:888:10)
at factory (D:\www\dtk_react_flow_www\wap\node_modules_webpack@4.38.0@webpack\lib\NormalModuleFactory.js:401:22)
at resolver (D:\www\dtk_react_flow_www\wap\node_modules_webpack@4.38.0@webpack\lib\NormalModuleFactory.js:130:21)
at asyncLib.parallel (D:\www\dtk_react_flow_www\wap\node_modules_webpack@4.38.0@webpack\lib\NormalModuleFactory.js:224:22)
at D:\www\dtk_react_flow_www\wap\node_modules_neo-async@2.6.1@neo-async\async.js:2830:7
at D:\www\dtk_react_flow_www\wap\node_modules_neo-async@2.6.1@neo-async\async.js:6877:13
at normalResolver.resolve (D:\www\dtk_react_flow_www\wap\node_modules_webpack@4.38.0@webpack\lib\NormalModuleFactory.js:214:25)
at doResolve (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\Resolver.js:184:12)
at hook.callAsync (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\Resolver.js:238:5)
at _fn0 (eval at create (D:\www\dtk_react_flow_www\wap\node_modules_tapable@1.1.3@tapable\lib\HookCodeFactory.js:33:10), :15:1)
at resolver.doResolve (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\UnsafeCachePlugin.js:37:5)
at hook.callAsync (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\Resolver.js:238:5)
at _fn0 (eval at create (D:\www\dtk_react_flow_www\wap\node_modules_tapable@1.1.3@tapable\lib\HookCodeFactory.js:33:10), :15:1)
at hook.callAsync (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\Resolver.js:238:5)
at _fn0 (eval at create (D:\www\dtk_react_flow_www\wap\node_modules_tapable@1.1.3@tapable\lib\HookCodeFactory.js:33:10), :27:1)
at resolver.doResolve (D:\www\dtk_react_flow_www\wap\node_modules_enhanced-resolve@4.1.0@enhanced-resolve\lib\DescriptionFilePlugin.js:42:38)

@ ./src/pages/index/index.js 38:36-59
@ ./src/pages/.umi-production/router.js
@ ./src/pages/.umi-production/umi.js
@ multi ./src/pages/.umi-production/umi.js

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] build: umi build
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] build 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! C:\Users\tql16\AppData\Roaming\npm-cache_logs\2019-08-05T07_47_22_305Z-debug.log

debug.log 内容：
0 info it worked if it ends with ok
1 verbose cli [ 'C:\Program Files\nodejs\node.exe',
1 verbose cli 'C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js',
1 verbose cli 'run',
1 verbose cli 'build' ]
2 info using [email protected]
3 info using [email protected]
4 verbose run-script [ 'prebuild', 'build', 'postbuild' ]
5 info lifecycle [email protected]prebuild: [email protected]
6 info lifecycle [email protected]build: [email protected]
7 verbose lifecycle [email protected]build: unsafe-perm in lifecycle true
8 verbose lifecycle [email protected]build: PATH: C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin;D:\www\dtk_react_flow_www\wap\node_modules.bin;C:\Users\tql16\AppData\Roaming\Tencent\QPlus\4.8.3071.0\QPlusRes\features\personalcenter\bin;C:\Users\tql16\AppData\Roaming\Tencent\QPlus\4.8.3071.0\QPlusRes\features\backgroundtool\bin;C:\Users\tql16\AppData\Roaming\Tencent\QPlus\4.8.3071.0\QPlusRes\features\kissweather\bin;C:\Users\tql16\AppData\Roaming\Tencent\QPlus\4.8.3071.0\QPlusRes\features\mirrorscreen\bin;C:\Users\tql16\AppData\Roaming\Tencent\QPlus\4.8.3071.0\Bin;C:\ProgramData\DockerDesktop\version-bin;C:\Program Files\Docker\Docker\Resources\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\Git\cmd;%JAVA_HOME%\bin;%JAVA_HOME%\jre\bin;C:\Program Files\nodejs;C:\Users\tql16\AppData\Local\Microsoft\WindowsApps;C:\Program Files\Microsoft VS Code\bin;"C:\Program Files\Java\jdk-11.0.1\bin; C:\Program Files\Java\jdk-11.0.1\jre\bin";;C:\Users\tql16\AppData\Local\Programs\Fiddler;C:\Users\tql16\AppData\Roaming\npm
9 verbose lifecycle [email protected]build: CWD: D:\www\dtk_react_flow_www\wap
10 silly lifecycle [email protected]build: Args: [ '/d /s /c', 'umi build' ]
11 silly lifecycle [email protected]build: Returned: code: 1 signal: null
12 info lifecycle [email protected]build: Failed to exec build script
13 verbose stack Error: [email protected] build: umi build
13 verbose stack Exit status 1
13 verbose stack at EventEmitter. (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\index.js:301:16)
13 verbose stack at EventEmitter.emit (events.js:198:13)
13 verbose stack at ChildProcess. (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
13 verbose stack at ChildProcess.emit (events.js:198:13)
13 verbose stack at maybeClose (internal/child_process.js:982:16)
13 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
14 verbose pkgid [email protected]
15 verbose cwd D:\www\dtk_react_flow_www\wap
16 verbose Windows_NT 10.0.17134
17 verbose argv "C:\Program Files\nodejs\node.exe" "C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js" "run" "build"
18 verbose node v10.16.0
19 verbose npm v6.9.0
20 error code ELIFECYCLE
21 error errno 1
22 error [email protected] build: umi build
22 error Exit status 1
23 error Failed at the [email protected] build script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]