This is a very particular issue that I am facing and I will have to go into the details to explain so please bear with me.

Background

I am working on a Hugo project with the Docsy theme and Docsy has a dev dependency on the npm library hugo-extended. This library has a post install scripts which downloads the Hugo binary pertaining to the current platform and attempts to execute it once to check if the correct version was downloaded.

If I install Docsy with npm install github:google/docsy#semver:0.11.0, the resulting package-lock.json doesn't include hugo-extended at all, which is what I want (we install Hugo ourselves and don't want the transitive dependency of Hugo Docsy brings). Installing Docsy like this works just fine (at least on the surface) on my Windows system and on most Linux based containers.

The Issue

But the issue crops up when trying to install Docsy in an Alpine linux based container. The error that crops up is due to the downloaded binary not being compatible with musl based systems like Alpine.

But, that is not the issue. The issue here is that running npm install github:google/docsy#semver:0.11.0 results in an attempt to install hugo-extended. Since hugo-extended is not in my package-lock.json, there should be no attempt to install hugo-extended. In fact using yarn instead, I don't face this issue as (seemingly) yarn doesn't try to install hugo-extended.

The diagnosis

Initially, I spent a lot of time trying to get the hugo binary working with alpine but as I mentioned before, I kept thinking that npm shouldn't even be attempting to install hugo-extended in the first place and I found the yarn actually doesn't. Which led me to try and find if the issue is with npm itself. Running npm install github:google/docsy#semver:0.11.0 gives a particular error message among others

git dep preparation failed

Searching around this issue led me to
https://github.com/npm/pacote/blob/bf1f60f58bb61f053262f54724edcacaadb221ce/lib/git.js#L152-L191
Here, I can see that npm tries to run npm install on any git based dependencies which results in attempting to install everything in the package.json of that git based dependency, *even if it isn't present in our package-lock.json`.

To me, this is an unpredictable behaviour. npm shouldn't be attempting to install the whole package.json of this dependency, even if it is doing that in a temp folder.

Note

We have workarounds for this but the fact that this issue doesn't happen with yarn is indicative that it's npm's implementation that is leading to this issue. I am not raising this issue as

1. I don't know if it should go to npm/cli or npm/pacote
2. Maybe some discussion is needed first

Here's the related issue and discussion which led to this post: kubernetes/website#49460 (comment)