Expo开发解决问题的过程

[timi-black]

expo start --web -c (清缓存启动)

Your JavaScript transform cache is empty, rebuilding (this may take a minute).
Starting Webpack on port 19006 in production mode.
[=================== ] 95% (11.0 seconds)(node:52976) UnhandledPromiseRejectionWarning: Error: It was not possible to generate splash screen '/usr/local/lib/node_modules/expo-cli/node_modules/@expo/webpack-config/web-default/icon.png'. This command requires version 1.10.0 of `sharp-cli`. 
You can install it using `npm install -g sharp-cli@1.10.0`. 

For prerequisites, see: https://sharp.dimens.io/en/stable/install/#prerequisites
    at new IconError (/@expo/webpack-pwa-manifest-plugin@1.2.4/src/errors/IconError.js:2:20)

根据提示安装

npm i -g npm sharp-cli@1.10.0

又报错了

/usr/local/bin/npx -> /usr/local/lib/node_modules/npm/bin/npx-cli.js
/usr/local/bin/npm -> /usr/local/lib/node_modules/npm/bin/npm-cli.js
/usr/local/bin/sharp -> /usr/local/lib/node_modules/sharp-cli/bin/cli.js

> sharp@0.22.1 install /usr/local/lib/node_modules/sharp-cli/node_modules/sharp
> (node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)

info sharp Downloading https://github.com/lovell/sharp-libvips/releases/download/v8.7.4/libvips-8.7.4-darwin-x64.tar.gz
/usr/local/lib/node_modules/sharp-cli/node_modules/sharp/install/libvips.js:83
          throw err;
          ^

Error: unable to verify the first certificate
    at TLSSocket.onConnectSecure (_tls_wrap.js:1058:34)
    at TLSSocket.emit (events.js:198:13)
    at TLSSocket._finishInit (_tls_wrap.js:636:8)
  TOUCH Release/obj.target/libvips-cpp.stamp
  CXX(target) Release/obj.target/sharp/src/common.o
../src/common.cc:25:10: fatal error: 'vips/vips8' file not found
#include <vips/vips8>
         ^~~~~~~~~~~~

根据错误提示搜索问题

brew install vips

安装成功后再次尝试

npm install -g sharp-cli@1.10.0

 sharp@0.22.1 install /usr/local/lib/node_modules/sharp-cli/node_modules/sharp
> (node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)

info sharp Detected globally-installed libvips v8.8.1
info sharp Building from source via node-gyp
Package libffi was not found in the pkg-config search path.
Perhaps you should add the directory containing `libffi.pc'
to the PKG_CONFIG_PATH environment variable
Package 'libffi', required by 'gobject-2.0', not found
gyp: Call to 'PKG_CONFIG_PATH="/usr/lib/pkgconfig:/usr/local/Homebrew/Library/Homebrew/os/mac/pkgconfig/10.14:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig" pkg-config --cflags-only-I vips-cpp vips glib-2.0 | sed s\/-I//g' returned exit status 0 while in binding.gyp. while trying to load binding.gyp

根据提示

vim ~/.bash_profile
添加:
export PKG_CONFIG_PATH="${PKG_CONFIG_PATH}:/usr/local/opt/libffi/lib/pkgconfig"

source ~/.bash_profile

再试尝试

npm install -g sharp-cli@1.10.0

终于成功了

XYSZM01652:~ wutianmei$ npm install -g sharp-cli@1.10.0
/usr/local/bin/sharp -> /usr/local/lib/node_modules/sharp-cli/bin/cli.js

> sharp@0.22.1 install /usr/local/lib/node_modules/sharp-cli/node_modules/sharp
> (node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)

info sharp Detected globally-installed libvips v8.8.1
info sharp Building from source via node-gyp
  TOUCH Release/obj.target/libvips-cpp.stamp
  CXX(target) Release/obj.target/sharp/src/common.o
  CXX(target) Release/obj.target/sharp/src/metadata.o
  CXX(target) Release/obj.target/sharp/src/stats.o
  CXX(target) Release/obj.target/sharp/src/operations.o
  CXX(target) Release/obj.target/sharp/src/pipeline.o
  CXX(target) Release/obj.target/sharp/src/sharp.o
  CXX(target) Release/obj.target/sharp/src/utilities.o
  SOLINK_MODULE(target) Release/sharp.node
+ sharp-cli@1.10.0
added 134 packages from 118 contributors in 48.834s

总结

• 安装包的过程中解决问题的方案往往都可以在错误提示中找到
• 使用 cnpm和yarn有时并不能成功安装所有的包,当多次尝试无果时我们要回到根源使用npm