经验教训 029：由于镜像配置有误导致 electron 安装失败

发生时间：2022-07-05
问题描述：在 Ubuntu 20.04 和 node v14.17.3 环境下，执行 npm i -D electron 失败，报错为「校验和不匹配」（详见下文）。
问题类别：软件开发
原因分析：
1. 谷歌搜索报错信息，有人说需要删除以前缓存的校验和文件。
2. 查看 ~/.cache/electron 及其子目录，发现确实存在 SHASUMS256.txt 文件。
3. 删除上述文件，重新运行 npm i -D electron，但依然报同样的错误。
4. 百般尝试后，发现执行如下命令来安装可以成功：
```
ELECTRON_MIRROR="https://npm.taobao.org/mirrors/electron/" npm i -D electron
```
1. 接下来很快发现是 electron 镜像路径没配置正确导致的问题。
- 之前访问https://npm.taobao.org/，会重定向到https://npmmirror.com/，并且后者提示「原淘宝 npm 域名即将停止解析」。
- 于是我就修改 electron 镜像路径：本来 npmmirror 主页给出的 electron 镜像路径为 https://npmmirror.com/mirrors/electron/，但我没使用这个路径，使用的是点击此路径后在网址栏显示的路径（如下所示）。
```
electron_mirror = "https://registry.npmmirror.com/binary.html?path=electron/"
```
1. 这样配置路径会导致什么问题呢？查看node_modules/electron/install.js及相关文件，发现：
- 安装 electron 镜像时，会下载一个校验和文件，该文件放在对应版本的 electron 目录下，下载地址按以下方式拼接得到的： ${electron_mirror}/${electron_version}/SHASUMS256.txt
- 按照我配置的 electron_mirror，会导致无法下载到正确的 SHASUMS256.txt，下载的是 electron 镜像主页（一个 html 文件）
- 因此，校验 SHASUMS256.txt 时会发现其格式不正确，从而报错。
解决方案：修改 electron 镜像路径为淘宝源：npm config set electron_mirror https://npm.taobao.org/mirrors/electron/，再重新安装。
实施结果：实测发现，可以成功安装国内镜像源里面的多个版本的 electron，如 7.3.3、8.5.5 、10.0.0 及 19.0.7 等。
经验总结：
1. 配置镜像地址时应该使用官方提供的网址，不要自行制作。
2. 定位 node.js 问题有个好处：源码就放在 node_modules 目录下，可以随便加调试打印，不用备份，反正重新安装又能生成原始文件。
3. 之前一直以为是 electron 与 node 版本不匹配导致的问题，还因此埋怨 electron 太不好用。可见，如果对问题浅尝辄止，不能寻根问底，往往会带来误解，得出错误的结论。

安装 electron 时的报错信息

在 Ubuntu 20.04 和 node v14.17.3 环境下，执行 npm i -D electron 失败，报错如下所示。

along:~$ npm i -D electron

> electron@19.0.7 postinstall /home/along/src/learn-electron/my-electron-app/node_modules/electron
> node install.js

Error: Generated checksum for "electron-v19.0.7-linux-x64.zip" did not match expected checksum.
    at Hash.<anonymous> (/home/along/src/learn-electron/my-electron-app/node_modules/sumchecker/index.js:133:20)
    at Hash.emit (events.js:375:28)
    at emitReadable_ (internal/streams/readable.js:550:12)
    at onEofChunk (internal/streams/readable.js:528:5)
    at readableAddChunk (internal/streams/readable.js:245:5)
    at Hash.Readable.push (internal/streams/readable.js:204:10)
    at Hash.Transform.push (internal/streams/transform.js:166:32)
    at done (internal/streams/transform.js:234:17)
    at internal/streams/transform.js:148:7
    at Hash._flush (internal/crypto/hash.js:71:3)
npm WARN my-electron-app@1.0.0 No repository field.

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! electron@19.0.7 postinstall: `node install.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the electron@19.0.7 postinstall 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!     /home/along/.npm/_logs/2022-07-05T03_30_36_254Z-debug.log

同样环境下，执行 npm i -D electron@10.0.0 同样失败，但报错信息不太一样（解析校验和文件失败）。

along:~$ npm i -D electron@10.0.0

> electron@10.0.0 postinstall /home/along/src/learn-electron/my-electron-app/node_modules/electron
> node install.js

Error: Could not parse checksum file at line 1: <!DOCTYPE html>
    at ChecksumValidator.parseChecksumFile (/home/along/src/learn-electron/my-electron-app/node_modules/sumchecker/index.js:83:15)
    at ChecksumValidator.validate (/home/along/src/learn-electron/my-electron-app/node_modules/sumchecker/index.js:106:10)
    at async /home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:110:21
    at async useAndRemoveDirectory (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/utils.js:10:18)
    at async /home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:75:13
    at async useAndRemoveDirectory (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/utils.js:10:18)
    at async downloadArtifact (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:65:12)
npm WARN my-electron-app@1.0.0 No description
npm WARN my-electron-app@1.0.0 No repository field.

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! electron@10.0.0 postinstall: `node install.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the electron@10.0.0 postinstall 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!     /home/along/.npm/_logs/2022-07-05T09_54_25_748Z-debug.log

同样环境下，执行npm i -D electron@8.0.0，最终显示成功，但其实也有跟安装 10.0.0 时一样的错误（导致 electron 没有完整安装），只不过被忽略掉了。

along:~$ npm i -D electron@8.0.0

> electron@8.0.0 postinstall /home/along/src/learn-electron/my-electron-app/node_modules/electron
> node install.js

(node:210739) UnhandledPromiseRejectionWarning: Error: Could not parse checksum file at line 1: <!DOCTYPE html>
    at ChecksumValidator.parseChecksumFile (/home/along/src/learn-electron/my-electron-app/node_modules/sumchecker/index.js:83:15)
    at ChecksumValidator.validate (/home/along/src/learn-electron/my-electron-app/node_modules/sumchecker/index.js:106:10)
    at async /home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:110:21
    at async useAndRemoveDirectory (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/utils.js:10:18)
    at async /home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:75:13
    at async useAndRemoveDirectory (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/utils.js:10:18)
    at async downloadArtifact (/home/along/src/learn-electron/my-electron-app/node_modules/@electron/get/dist/cjs/index.js:65:12)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:210739) UnhandledPromiseRejectionWarning: Unhandled promise rejection.
This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch().
To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict`
(see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:210739) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated.
In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
npm WARN my-electron-app@1.0.0 No description
npm WARN my-electron-app@1.0.0 No repository field.

+ electron@8.0.0
added 91 packages from 93 contributors in 5.49s

9 packages are looking for funding
  run `npm fund` for details

安装 electron 时的报错信息#

安装 electron 时的报错信息