Add libev

[Pierre Labastie]

The conclusion of ticket #13992 is that libev is not a drop-in replacement of libevent, but now, the question is whether they can sit together. This means:

• installing libev
• test the packages dependant on libevent to see whether they still build. the list of packages is on ticket #13992

[Pierre Labastie]

For easier reference, here is the list of packages dependant on libevent:

• ntp (optional)
• avahi (optional)
• nghttp2 (optional, but seems to depend on libev rather)
• links (recommended)
• mariadb (recommended)
• unbound (optional)
• qtwebengine (optional)
• firefox (recommended, used by libxul.so)
• seamonkey (recommended)
• thunderbird (recommended)
• transmission (required)

[Pierre Labastie]

We have to solve the problem of build ordering: if libevent is built before libev, event.h and libevent are the one from libev, then it might break applications expecting libevent. So libevent should be built after libev. But what if libev is rebuilt after (for example, if there is a new release of libev)? So I think we should prevent event.h and libevent from being installed by libev.

It is not possible directly, but it is possible by tweaking Makefile.am and running autogen.sh. I'll try with that.

[Bruce Dubbs]

Have you done a diff between the two versions of event.h?

[Pierre Labastie]

They are completely different. Actually, the libev doc tells they are not compatible. You have to choose between using one or the other.

I think we should keep libevent (with less performance but more features) as is, and add only the libev bits that are needed for nghttp2 (unless we decide not to add libev at all, and live without nghttp2 apps).

[Pierre Labastie]

Looks like it is too much burden for not much gain (only have some more curl tests passing). Closing as wontfix.