Python Pip Module dependency resolver

#!/usr/bin/env perl
use strict;
use warnings;

# This script is a (probably naive) attempt at writing a recursive dependency resolver for the Python package index (PyPi)
# A list of (space seperated) Python Package names provided on the command line are the starting point
# Each package in that list is added to a graph, then every node(vertex) in that graph has edges defined between the node itself
# and each of it's dependencies (which become their own nodes as a result)
# Every node in the graph is iterated through, has it's dependencies(edges) defined, and the process is repeated until
# the graph stops changing. Once there are no more dependencies to find, it prints out a (alphabetically sorted) list
# of every package that would be required to install every package given as an argument to this script. Note that this list
# WILL INCLUDE the packages that were initially provided as part of the list.

use JSON;
use Graph;

# Our main dependency graph objects
# We need two so we can check if the graph changed between dependency runs
# When the two graphs stay the same after a dependency run, we know our graph is complete
my $Agraph = Graph->new();
my $Bgraph = Graph->new();

# Accepts a list of python packages to check dependencies for
# Returns a list of python packages the arguments depend upon
# Note that this function is NOT RECURSIVE. It ONLY provides the direct dependencies.
sub get_deps {
    my $ret = [];
    my $json = JSON->new;
    foreach my $package ( @_ ) {
        my $curl = `curl -s "https://pypi.org/pypi/$package/json"`;
        my $reqs = $json->decode($curl)->{info}->{requires_dist};
        if (defined($reqs)) {
            foreach my $dep (@$reqs) {
                $dep =~ s/[^a-zA-Z0-9-].*$//;
                push(@$ret, $dep);
            }
        }
    }
    return $ret;
}

# @ARGV is a list of packages we need to find all dependencies for and is the roots of our dependency graph
foreach my $package (@ARGV) {
    $Agraph->add_vertex($package);
}

# A list of packages we have already gotten dependnecies for so we don't check twice
my $checked = [];

# Loop until our graphs stop changing between dependency runs
while ( $Agraph ne $Bgraph ) {
    $Bgraph = $Agraph->deep_copy();

    # Check every single vertice in our graph
    my @vertlist = $Agraph->vertices;
    foreach my $package (@vertlist) {
        # If we haven't checked this package before, get it added to the graph with all of it's dependencies
        if (! grep( /^$package$/, @$checked )) {
            my $deplist = get_deps($package);
            foreach my $dep (@$deplist) {
                $Agraph->add_edge($package, $dep);
            }
            # Add this package to our list of already checked packages so we don't waste time
            push(@$checked, $package);
        }
    }
}

my @fulldeplist = sort $Agraph->vertices;
foreach my $package (@fulldeplist) {
    print "$package\n";
}