Unable to install NPM packages due to path length constraint using NPM 5.X - npm

Question

I'm running Windows 10, NPM v5.5.1, and node v8.9.1.
Edit: I have since updated to node v8.9.4 and npm v5.6.0. The problem remains unchanged.
I set up my development environment on this machine about 2 months ago. I'm using Angular CLI to build my client apps.
Everything was going fine. I added a few packages via NPM without a problem, such as Gulp and ngx-bootstrap. Then I started to run into errors on some of my package installs.
The errors are:
npm ERR! code PATH_LENGTH_EXCEEDED
npm ERR! errno PATH_LENGTH_EXCEEDED
npm ERR! request to https://registry/npmjs.org/{{package}} failed, reason: path length constraint exceeded
npm ERR! A complete log of this run can be found in:
npm ERR! {{npm_cache path}}\_logs\2018-02-08T14_43_40_856Z-debug.log
The contents of that log file are:
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 'install',
1 verbose cli 'ngx-cookie-service',
1 verbose cli '--save' ]
2 info using npm#5.5.1
3 info using node#v8.9.1
4 verbose npm-session d55be12849534a0a
5 silly install loadCurrentTree
6 silly install readLocalPackageData
7 silly fetchPackageMetaData error for ngx-cookie-service#latest request to https://registry.npmjs.org/ngx-cookie-service failed, reason: path length constraint exceeded
8 verbose type system
9 verbose stack FetchError: request to https://registry.npmjs.org/ngx-cookie-service failed, reason: path length constraint exceeded
9 verbose stack at ClientRequest.req.on.err (C:\Program Files\nodejs\node_modules\npm\node_modules\pacote\node_modules\make-fetch-happen\node_modules\node-fetch-npm\src\index.js:68:14)
9 verbose stack at emitOne (events.js:116:13)
9 verbose stack at ClientRequest.emit (events.js:211:7)
9 verbose stack at TLSSocket.socketErrorListener (_http_client.js:387:9)
9 verbose stack at emitOne (events.js:116:13)
9 verbose stack at TLSSocket.emit (events.js:211:7)
9 verbose stack at emitErrorNT (internal/streams/destroy.js:64:8)
9 verbose stack at _combinedTickCallback (internal/process/next_tick.js:138:11)
9 verbose stack at process._tickCallback (internal/process/next_tick.js:180:9)
10 verbose cwd C:\Development\test
11 verbose Windows_NT 10.0.15063
12 verbose argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "ngx-cookie-service" "--save"
13 verbose node v8.9.1
14 verbose npm v5.5.1
15 error code PATH_LENGTH_EXCEEDED
16 error errno PATH_LENGTH_EXCEEDED
17 error request to https://registry.npmjs.org/ngx-cookie-service failed, reason: path length constraint exceeded
18 verbose exit [ 1, true ]
I researched this, and found the Windows 10 file path 260 character limitation. I thought that npm version 3.1.0 should have fixed this issue, but I decided to followed the instructions in this answer, because I'm still running into this issue despite using NPM v5.5.1.
I found that my version of Windows was prior to the roll out of the feature that lets you disable this limitation. I updated to Version 1703 (OS Build 15063.483), and to enable Win32 long paths.
Yet I'm still getting the error, and unable to install a variety of npm packages.
In testing to see if it was an issue with packages that have a lot of dependencies, I tried installing or reinstalling a couple of other packages.
Some fail with the errors above. Others succeed with the following warnings:
npm WARN Unexepcted warming for https://registry.npmjs.org/: Miscellaneous Warning PATH_LENGTH_EXCEEDED: request to https://registry.npmjs.org/{{package name}} failed, reason: path length constraint exceeded
npm WARN Using stale package data from https://registry.npmjs.org/ due to a request error during validation
Packages throwing the error include:
jslint
ngx-cookie-service
chart.js
angular-cli
Packages that throw the warnings include:
font-awesome
#angular/cli
moment
ngx-bootstrap
bootstrap
jasmine
I suspect that something has changed, either in a policy on my workstation, or in our network security, that is causing this. All of the packages that succeed seem to be packages that I had previously installed, either as a direct install, or as a dependency of #angular/cli (one of the first packages I installed). I'm assuming that the stale package data warning indicates that whatever problem I have with the path length is preventing updated data being retrieved, and therefore npm is falling back to cached data from previous installations of the selected package and its dependencies.
So now I'm stumped as to how to diagnose exactly where the issue is happening. If its a security policy that changed, then I need to be able to describe exactly what is being blocked so that I can work with our security department to fix this. But the only information I can find about the PATH_LENGTH_EXCEEDED errors lead me to old information about versions of npm prior to 3.1.0.
How can I identify the source of this problem?

Answer 1

After additional searching, I found references to path length exceeded with regards to SSL/TLS certificate authorities. I tested this issue by changing the npm registry to use http instead of https (note: this is a temporary step only; I have turned https back on once I verified the issue):
npm config set registry http://registry.npmjs.org/
This allowed me to install the problematic packages.
It seems the underlying cause is SSL Inspection performed by our network security team. The decryption, inspection, and re-encryption process, and subsequent changes in the Issuing Authority on the certificate, apparently triggers this error.