NPM-依赖项需要多个版本的软件包，但仅安装了一个版本

Question

After npm install on clean environment, I get following problem with b package:

npm ls b   

a@2.0.6
├── b@3.0.0
├─┬ c@3.0.1
│ └── UNMET DEPENDENCY b@^1.0.0
└─┬ d@4.1.1
  └─┬ c@2.1.0
    └── UNMET DEPENDENCY b@^1.0.0

npm ERR! missing: b@^1.0.0, required by c@3.0.1
npm ERR! missing: b@^1.0.0, required by c@2.1.0

This obviously causes errors, as package c needs b@^1.0.0 , but receives b@3.0.0 .

I struggled to force npm to install both versions as if they were different packages. Tried going through npm docs, package-locks, and shinkwrap, but with no success. How can I solve this problem?

Environment info:

OS: macOS High Sierra 10.13.4
npm: 6.10
node: v8.8.1

Answer 1

Playing around I noticed, that a lot of packages had UNMET DEPENDENCY. Following procedure fixed the problem:

rm -rf node_modules
npm cache clean --force
npm install

After cleaning npm cache the issue is completely resolved:

a@2.0.6
├── b@3.0.0
├─┬ c@3.0.1
│ └── b@^1.0.0
└─┬ d@4.1.1
  └─┬ c@2.1.0
    └── b@^1.0.0

Strange bug.