Weechat: Crash when PHP packages are not installed

[Zarthus]

WeeChat crashes on devel WeeChat 2.0-dev (git: v1.9-353-g157dc811a), the cause is that php7.x-embed is not installed on the system. https://github.com/weechat/weechat/issues/1078#issuecomment-334575574

Original post can be found here, comments have been compressed into gists as the backtraces are quite lengthy: https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-a_op-zarthus-md

[flashcode]

Hi,
How can I reproduce the crash?
Can you try to start WeeChat without scripts? (weechat -s). And if this still crashes, without plugins: weechat -p

[Zarthus]

1. https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-comment-1-zarthus-md (initial reproduction steps)
2. https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-comment-2-zarthus-md (mentions which python plugins crashed for me; determined to be caused by import random)
3. https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-comment-3-zarthus-md (crash backtrace of prism.py loaded)
4. https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-comment-4-zarthus-md (/debug libs)
5. https://gist.github.com/Zarthus/af57be8e65675fbbc55ef692126fbdfb#file-comment-5-zarthus-md (minimal reproduction steps)

[flashcode]

So the problem happens when there's no php installed (or not all required packages).
Currently the Debian packages in weechat.org repository embeds php plugin but there's a dependency problem: the php packages are not required. That means weechat can be installed without php, which causes the crash.
The solution is to install libphp7.1-embed (or libphp7.0-embed in Stretch).
I'm looking why it crashes though (it should not crash when the lib is not found).

[flashcode]

Hmm still not working in debian packaging.