[CMake] getting the rpath right on osx

[Boudewijn Rempt]

I checked the manual and the blog post about rpath on osx, but I'm still
confused, and still not getting it right...

I build and installed Qt 5.6 alpha like this:

./configure -prefix /Users/boudewijnrempt/kf5/i

Then I made a small test project, consisting of nothing but a main that links to QtCore.

If I build that with qmake, with this .pro file:

QT       += core
QT       -= gui
TARGET = rpathqmake
CONFIG   += console
CONFIG   -= app_bundle
TEMPLATE = app
SOURCES += main.cpp

The r-path is set:

Boudewijns-Mac-mini:test boudewijnrempt$ otool -L rpathqmake
rpathqmake:
     @rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.6.0, current version 5.6.0)
     /System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
     /System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
     /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
     /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1213.0.0)

Boudewijns-Mac-mini:test boudewijnrempt$ otool -L rpathqmake | grep -i rpath
rpathqmake:
     @rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.6.0, current version 5.6.0

If I try a minimal cmakelists.txt, the rpath isn't set, I tried with and without all those RPATH related lines,
they don't seem to make a difference. I'm using cmake 3.3.2.

cmake_minimum_required(VERSION 2.8.12)
cmake_policy(SET CMP0042 NEW)
set(CMAKE_MACOSX_RPATH ON)
SET(CMAKE_SKIP_BUILD_RPATH TRUE)
SET(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
set(REQUIRED_QT_VERSION 5.3.0)
find_package(Qt5 ${REQUIRED_QT_VERSION} CONFIG REQUIRED Core)
add_executable(rpathcmake main.cpp)
target_link_libraries(rpathcmake Qt5::Core)
install(TARGETS rpathcmake DESTINATION /Users/boudewijnrempt/kf5/i/bin)

Only adding something like this makes it work:

set_target_properties(rpathcmake PROPERTIES INSTALL_RPATH "/Users/boudewijnrempt/kf5/i/lib")

Which I'm pretty sure is something I don't want.

Boudewijns-Mac-mini:test boudewijnrempt$ make install
[100%] Built target rpathcmake
Install the project...
-- Install configuration: ""
-- Up-to-date: /Users/boudewijnrempt/kf5/i/bin/rpathcmake
Boudewijns-Mac-mini:test boudewijnrempt$ otool -L /Users/boudewijnrempt/kf5/i/bin/rpathcmake 
/Users/boudewijnrempt/kf5/i/bin/rpathcmake:
     @rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.6.0, current version 5.6.0)
     /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
     /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)
Boudewijns-Mac-mini:test boudewijnrempt$ ~/kf5/i/bin/rpathcmake 
dyld: Library not loaded: @rpath/QtCore.framework/Versions/5/QtCore
   Referenced from: /Users/boudewijnrempt/kf5/i/bin/rpathcmake
   Reason: image not found
Trace/BPT trap: 5
Boudewijns-Mac-mini:test boudewijnrempt$ otool -L /Users/boudewijnrempt/kf5/i/bin/rpathcmake 
/Users/boudewijnrempt/kf5/i/bin/rpathcmake:
     @rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.6.0, current version 5.6.0)
     /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 120.0.0)
     /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)

What should I do?

-- 
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org