How to get information about what went wrong during module installation PS 1.7

[theillo 14]

I need to update my PS to 1.7 because my server is updating PHP. 

I have a lot of custom modules, thousands of lines of code, and don't wanna have to rewrite them.

Luckily, many of them installed with no problems.

But some, just give me a generic error "Installation of module mymodule failed. Unfortunately, the module did not return additional details."

How can I further debug this error?

Obviously, debug mode is already turned on...

[Rhobur 145]

The server logs (apache/nginx.php)