LibXml for Linux is not picked up by CMake about conan HOT 6 CLOSED

Hi Marco,

CMake needs a custom findXXX.cmake file in every package in order to find them trough a find_package(XXX). My packages do not provide yet a findXXX.cmake. I will upload soon!

Actually, CMAKE_LIBRARY_PATH and CMAKE_INCLUDE_PATH are pointing to your libxml packages, but find_package do not use those variables to find the sources (yeah, it's annoying). Those custom find_package files do a lot of crazy things looking in common paths, appending common names and many other, but never look in CMAKE_LIBRARY_PATH.

Meanwhile you can omit the use of find_package and just link with CONAN_LIBS_LIBXML2 or the global CONAN_LIBS

Thanks for try it Marco!
Cheers

from conan.

Hi,

Well, you probably know CMake better than I do to be honest :-) I never looked at this in detail, but up till now I have been using these to supply the path to my local installs of boost, like so:

CMAKE_INCLUDE_PATH=/usr/local/personal/include CMAKE_LIBRARY_PATH=/usr/local/personal/lib CC=gcc-5 CXX=g++-5 cmake ../../../ -G Ninja -DCMAKE_EXPORT_COMPILE_COMMANDS=TRUE -DWITH_LATEX=FALSE && ninja -j5

This has worked fine for me locally, with the personal boost version taking precedence over the system installed one (and no changes required in the find boost etc). I also did this for windows using NuGet packages (LibXml) and it worked as well. Finally I did a quick search and found some other guys doing something similar for Qt on Windows [1]. I'm wondering - could it be CMake has changed behaviour recently since you guys looked at it?

Cheers

Marco

[1] http://stackoverflow.com/questions/10571249/cmake-qt-and-cmake-include-path

from conan.

Interesting! I looked again to CONAN_BASIC_SETUP and we are not setting directly CMAKE_INCLUDE_PATH and CMAKE_LIBRARY_PATH, I was wrong.

We are just calling to:

INCLUDE_DIRECTORIES(${CONAN_INCLUDE_DIRS}) 
LINK_DIRECTORIES(${CONAN_LIB_DIRS})

So maybe there is some unknow (by me) behaviour with CMAKE_INCLUDE_PATH and CMAKE_LIBRARY_PATH.

Thanks so much, I will try it!

PD: I think the key is that the findXXX recipes calls to find_library, and find_library looks in custom paths and "system" paths. Probably setting CMAKE_LIBRARY_PATH and CMAKE_INCLUDE_PATH will add places to look as "system" paths. Looks good!

from conan.

excellent, great news!

from conan.

It works!

I've open a PR, it will be (at least we find some problem) in conan 0.6
You can paste these lines after CONAN_BASIC_SETUP() call to fix all find_packages until we release conan 0.6

SET(CMAKE_INCLUDE_PATH ${CONAN_INCLUDE_DIRS} ${CMAKE_INCLUDE_PATH})
SET(CMAKE_LIBRARY_PATH ${CONAN_LIB_DIRS} ${CMAKE_LIBRARY_PATH})

Thanks a lot, its a big improvement! 👍

from conan.

No worries! I'll wait for v0.6 - it will get automatically picked up by the CI :-) I'll report back then.

Muchas gracias!

from conan.