I have switched Apache to prefork mode and everything works fine.

But I want to set Apache to mpm-event. Is Xdebug compatible with this mode?

If yes then it seems that the problem is in XDebug compilation.
How can I force phpize to pick correct headers?
There is only one phpize on my server for sure, so there is no way to confuse versions or something like that.

Tried "zts-phpize"

and even

./configure --with-php-config=/etc/alternatives/zts-php-config7

Result is the same.

Failed loading /usr/lib64/php-zts/7.0/modules/xdebug.so: /usr/lib64/php-zts/7.0/modules/xdebug.so: undefined symbol: compiler_globals

SOLVED

Using "zts-phpize"
AND custom config file for ZTS
./configure --with-php-config=/etc/alternatives/zts-php-config7

Solved the issue, I was just looking to the old logs.

I think it would be nice to somehow mention in documentation this flow for ZTS configuration.
Thank you!

The use of "zts-phpize" is very much not standard to either PHP or Xdebug itself. It seems to be a feature of some distributions, which I can't all support.

We do have some information about phpize with using --with-php-config though at https://xdebug.org/docs/faq#custom-phpize

If you would like to draft an extra FAQ section, or expand on the existing one, feel free to send that to me, or even better would be a pull request for it through github: https://github.com/xdebug/xdebug.org/blob/master/html/docs/include/features.php#L1327

As there is nothing really to fix on my side for this, I am resolving this issue.