rip-git: inteligently guess name of packed refs

[noraj]

$ rip-git -v -u http://censored/.git/ -o repo2 -t 10 -g
[i] Downloading git files from http://censored/.git/
[i] Auto-detecting 404 as 200 with 3 requests
[i] Getting correct 404 responses
[i] Using session name: fFqxEqjj
[d] found COMMIT_EDITMSG
[d] found config
[d] found description
[d] found HEAD
[d] found index
[!] Not found for packed-refs: 404 Not Found
[!] Not found for objects/info/alternates: 404 Not Found
[!] Not found for info/grafts: 404 Not Found
[d] found logs/HEAD
[d] found objects/7e/126c5c6151f8dd36abda39f0d7cd13fdb4646f
[d] found objects/a5/7903d406eeb9e7b7d0095bf4534be15322929f
[d] found objects/e9/110f8730ae517674dcc09651eb570aae7de549
[d] found objects/f9/c6bf17ec7eb376fb50ebac935328623aedb0cc
[d] found objects/d9/0016c0a550394b2051d65a817f1e658aa65892
[d] found objects/6c/5d9264a4f05e2b7d753beda8d40f2f69a714c3
[d] found objects/c7/54ac17f47495e396913993ff48fd10eb70723e
[d] found objects/4f/863231bf62ae8e337df2cdb73832b8c9842011
[d] found objects/ff/fc3436fdc898c0bbff7e134c64ddcac4d4d7b8
[d] found objects/43/2edd2aca6787c882fa2ea3edf3f1c5e224c81e
[d] found objects/2c/66d164f4008c9b6d2dce7f3ee998042f7a7c7d
[d] found refs/heads/master
[!] Please install Parallel::Prefork CPAN module for parallel requests
[i] Running git fsck to check for missing items
Checking object directories: 100% (256/256), done.
[i] Got items with git fsck: 0, Items fetched: 0
[!] No more items to fetch. That's it!
[!] Performing intelligent guessing of packed refs
Undefined subroutine &main::permutations called at /usr/bin/rip-git line 404.

https://github.com/kost/dvcs-ripper/blob/0672a34f35de62143859e49f178928148b97c973/rip-git.pl#L404

[noraj]

Am I missing a dependency?

[noraj]

Similar for -x

[!] Performing pure brute force guessing of packed refs
Undefined subroutine &main::variations_with_repetition called at /usr/bin/rip-git line 353.