How to enable display_errors with .htaccess

I have the following environment on one server:

1. dev.domain.com for the development
2. test.domain.com for the tests
3. www.domain.com is the working production

For the development environment I would like to see all PHP errors (includ开发者_如何学JAVAing parse errors). Unfortunately the PHP configuration is quite strict. It does not allow to set the display_errors within the PHP file. It means that

ini_set("display_errors", 1);

and all variants of it are not working. The following works fine within the .htassess file:

php_flag display_errors "1"

Thus, my idea was to do something like this:

if(HOST==dev.domain.com) {
    php_flag display_errors "1"
}

I tried SetEnvIf, RewriteCond, IfDefine and other variants, but without success.

Is there somehow a way to do it?

As I mentioned in my comment, you can set display_errors using ini_set(). However, it won't help with parse errors as noted in the manual

Can you make changes to the VirtualHost sections for each site? If so, add the php_flag in there.

If not, why not just have a different .htaccess file per site?

Just ignore the .htaccess file within your version control system and create a separate file for each set of settings on each server.