[gwright]

[Edit: It seems that I was mistaken but I'm leaving this up to illustrate the confusion. In my experience "second to last" isn't common and "next to last" is much more common, which I think is why I was confused because I thought they were different, but apparently they are the same. I wonder if there is a regional usage pattern to these phrases. ]

This seems like mistake or a non-standard usage of the english phrase "second to last". Given a git log of:

    $ git log --oneline
    15e0437 - (HEAD -> master) this is the third commit
    f82d1fd - this is the second commit
    9180c17 - initial commit

I would call "f82d1fd" the "next to last commit" and it can be referred to as HEAD~ I would call "9180c17" the "second to last commit" and it can be referred to as HEAD~2

[q3k]

I don't know (definitely not a native English speaker), but Wikitionary seems to agree with me: https://en.wiktionary.org/wiki/second_to_last#English .

[gwright]

Well, I think you may be right. See my edit above. I suspect this is a regional usage pattern and I've just always been in places where "next to last" would be used and not "second to last" so I was thinking they were different, but they apparently are the same!

Learn something new every day.

[gwright]

Here is an ngram analysis with a British corpus

https://books.google.com/ngrams/graph?content=second+last%2C...

And here is one with an American corpus:

https://books.google.com/ngrams/graph?content=second+last%2C...

[q3k]

Nice tool. You should expand the search range to include 2018/2019. Quite a significant change happened since then.