bundle viz without gem installation

[and0x000]

Describe the problem as clearly as you can

The associated gems must also be installed via bundle install(1).

bundler viz requires the gems to be be installed, even if there is a Gemfile.lock (e.g from bundle lock).

From my point of view, the lock file contains all the necessary information for generating the graph. Therefore I do not see the need for the gems to be actually installed.

As for my use case:
I want to generate the dependency graph of my gems in my a generic CI pipeline. The need for actually installing the gems would e.g. require the resolution of additional dependencies for native extensions inside the CI. I deem this unnecessary overhead.

related to rubygems/bundler#1471
related to rubygems/rubygems#3342

Both mention what this issue is about, but for a different reason.

Which command did you run?

bundle viz

What were you expecting to happen?

Generate dependency graph from Gemfile.lock alone.

What actually happened?

bundle viz required the gems to be installed.

If not included with the output of your command, run bundle env and paste the output below

Bundler             2.1.4
  Platforms         ruby, x86_64-linux
Ruby                2.7.1p83 (2020-03-31 revision a0c7c23c9cec0d0ffcba012279cd652d28ad5bf3) [x86_64-linux]
  Full Path         /usr/share/rvm/rubies/ruby-2.7.1/bin/ruby
  Config Dir        /etc
RubyGems            3.1.2

[deivid-rodriguez]

This sounds reasonable to me in principle.