maybe you can try again? A couple days ago I got the same error messages like you. Today I try again with php 5.3.20 and PHP 5.4.10, and load succesfully without that error message

hmmm
I have 2 computer each with Ubuntu 12.10 and 5.4.6. On one computer, with php ubuntu stock. Another computer with php build and compiled by myself (5.4.10 and 5.3.20). Checking with php ubuntu stock, yes, I got the same error, while on another, successfully loaded...

I'm not used to compile from source, maybe I go the wrong way.

But I tried several times before posting this note.

You got the error with php 5.4?

Under what conditions you do not have an error?

Could you share your *.so ?

I have tested with PHP 5.4.6, 5.4.7, 5.4.8, 5.4.9, and built module with it, no error

I have tried too, transfer my so to 'ubuntu stock one', got this error message (module built with 5.4.6, compiled myself):

PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/php5/20100525/git2.so' 
- /usr/lib/php5/20100525/git2.so: undefined symbol: git_tree_create_fromindex in Unknown on line 0

What I do not understand is that you get a compile and use.

I should not compile correctly, or make improper handling

I got git2.so compiled and used because compiled it against PHP from php.net, not against ubuntu's one, eventhough I use Ubuntu OS 12.10. On PHP packages from ubuntu, there are about 60 patches, but I don't know much about C so I don't know which patch make git2 failed loaded on PHP packages.

I understand. I'll try to compile php myself.
I had already done that once or twice I should succeed.

This is a dev server, so I can afford;)