/usr/lib/ruby/vendor_ruby/grit/commit.rb:152:in `list_from_string': undefined method `split' for nil:NilClass (NoMethodError)

[drt24]

When executing on this git repository: https://android.googlesource.com/kernel/goldfish.git

$ ./git-graph.rb /local/scratch/drt24/android/clones/kernel/goldfish

I get lots of lines like:

unknown header '' in commit de9c9f86be0dc3495de98dc65c80abe6e7c7d643
unknown header '' in commit de9c9f86be0dc3495de98dc65c80abe6e7c7d643
unknown header '' in commit de9c9f86be0dc3495de98dc65c80abe6e7c7d643
unknown header '' in commit de9c9f86be0dc3495de98dc65c80abe6e7c7d643
unknown header '' in commit de9c9f86be0dc3495de98dc65c80abe6e7c7d643
unknown header 'mergetag' in commit ce6fbaf160628df62ec953c701d5fc547484257a

And then:

/usr/lib/ruby/vendor_ruby/grit/commit.rb:152:in `list_from_string': undefined method `split' for nil:NilClass (NoMethodError)
    from /usr/lib/ruby/vendor_ruby/grit/commit.rb:125:in `find_all'
    from /usr/lib/ruby/vendor_ruby/grit/commit.rb:93:in `lazy_source'
    from /usr/lib/ruby/vendor_ruby/grit/lazy.rb:31:in `block (2 levels) in lazy_reader'
    from ./git-graph.rb:22:in `find_children'
    from ./git-graph.rb:301:in `block in <main>'
    from ./git-graph.rb:299:in `each'
    from ./git-graph.rb:299:in `<main>'

I am running Ubuntu 14.04.1 LTS 3.13.0-35-generic x86_64 with ruby 1.9.3p484 (2013-11-22 revision 43786) [x86_64-linux], ruby-fast-xs 0.8.0-3build1 and ruby-grit 2.5.0-1.

[jerith666]

As with issue #7, this may be unfixable without porting to a different underlying git library. I'll at least see if I can reproduce it, though.

[jerith666]

I get a slightly different error:

/usr/local/lib/ruby/gems/1.9.1/gems/grit-2.5.0/lib/grit/commit.rb:152:in `list_from_string': can't convert nil into String (TypeError)
from /usr/local/lib/ruby/gems/1.9.1/gems/grit-2.5.0/lib/grit/commit.rb:125:in `find_all'
from /usr/local/lib/ruby/gems/1.9.1/gems/grit-2.5.0/lib/grit/commit.rb:93:in `lazy_source'
from /usr/local/lib/ruby/gems/1.9.1/gems/grit-2.5.0/lib/grit/lazy.rb:31:in `block (2 levels) in lazy_reader'
from ../graphing.github/git-graph.rb:22:in `find_children'
from ../graphing.github/git-graph.rb:301:in `block in <main>'
from ../graphing.github/git-graph.rb:299:in `each'
from ../graphing.github/git-graph.rb:299:in `<main>'

My guess is that we're running into grit not knowing about a new mergetag commit header field described here.

There's some chance that https://github.com/gitlabhq/grit already contains a fix for this. If not, they may be open to implementing such a fix. Could you try out their fork of grit and see if it works?