gel ignores gemspec definition

[yosiat]

Hi!

Given this gem file:

# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem "rails", "6.1.0"
gem "active_record_distinct_on"

bundler 2.1.4, throws this error:

Bundler could not find compatible versions for
gem "activemodel":
  In snapshot (Gemfile.lock):
    activemodel (= 6.0.3.4)

  In Gemfile:
active_record_distinct_on was resolved to
0.1.7, which depends on
activerecord (>= 4.2, < 6.1) was resolved
to 6.0.3.4, which depends on
        activemodel (= 6.0.3.4)

rails (= 6.1.0) was resolved to 6.1.0,
which depends on
      activemodel (= 6.1.0)

Running `bundle update` will rebuild your
snapshot from scratch, using only
the gems in your Gemfile, which may resolve the
conflict.

while gel install runs successfully.

active_record_distinct_on gemspec specifies - < 6.1 on rails version - https://github.com/alecdotninja/active_record_distinct_on/blob/master/active_record_distinct_on.gemspec#L20

Looks like a bug in gel, or something else which I don't understand.