1.7.4: pkg-config file (wrong includedir)

[tgurr]

In 1.7.2 everything looked okay:

prefix=/usr/x86_64-pc-linux-gnu
exec_prefix=${prefix}
libdir=/usr/x86_64-pc-linux-gnu/lib
includedir=/usr/x86_64-pc-linux-gnu/include/jsoncpp

Name: jsoncpp
Description: A C++ library for interacting with JSON
Version: 1.7.2
URL: https://github.com/open-source-parsers/jsoncpp
Libs: -L${libdir} -ljsoncpp
Cflags: -I${includedir}

and in 1.7.4 at least the includedir looks wrong to me:

prefix=/usr/x86_64-pc-linux-gnu
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}//usr/x86_64-pc-linux-gnu/include/jsoncpp

Name: jsoncpp
Description: A C++ library for interacting with JSON
Version: 1.7.4
URL: https://github.com/open-source-parsers/jsoncpp
Libs: -L${libdir} -ljsoncpp
Cflags: -I${includedir}

[cdunn2001]

See #493. 1.7.4 is a "pre-release tag". We might need to revert, but hopefully you and @zorun can find a workable solution.

[zorun]

It's apparently hard to make everyone happy...

@tgurr can you provide the arguments you pass to cmake? Also, was 1.7.3 fine for you? Because as mentioned in #493, 1.7.3 was broken for Archlinux.

For reference, here is the cmake invocation and resulting pkg-config file on Archlinux:

cmake \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_INSTALL_PREFIX=/usr \
    -DBUILD_SHARED_LIBS=ON \
    -DBUILD_STATIC_LIBS=OFF

prefix=/usr
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: jsoncpp
Description: A C++ library for interacting with JSON
Version: 1.7.4
URL: https://github.com/open-source-parsers/jsoncpp
Libs: -L${libdir} -ljsoncpp
Cflags: -I${includedir}

[tgurr]

Here is what it looks like with 1.7.3:

prefix=/usr/x86_64-pc-linux-gnu
exec_prefix=${prefix}
libdir=lib
includedir=/usr/x86_64-pc-linux-gnu/include/jsoncpp

Name: jsoncpp
Description: A C++ library for interacting with JSON
Version: 1.7.3
URL: https://github.com/open-source-parsers/jsoncpp
Libs: -L${libdir} -ljsoncpp
Cflags: -I${includedir}

The CMake arguments we pass:

-DCMAKE_COLOR_MAKEFILE:BOOL=TRUE
-DCMAKE_VERBOSE_MAKEFILE:BOOL=TRUE
-DCMAKE_BUILD_TYPE:STRING=None
-DCMAKE_C_FLAGS:STRING=-pipe -O2 -march=native
-DCMAKE_CXX_FLAGS:STRING=-march=native -O2 -pipe
-DCMAKE_AR:PATH=x86_64-pc-linux-gnu-ar
-DCMAKE_RANLIB:PATH=x86_64-pc-linux-gnu-ranlib
-DCMAKE_NM:PATH=x86_64-pc-linux-gnu-nm
-DCMAKE_C_COMPILER:PATH=x86_64-pc-linux-gnu-cc
-DCMAKE_CXX_COMPILER:PATH=x86_64-pc-linux-gnu-c++
-DCMAKE_INSTALL_PREFIX:PATH=/usr/x86_64-pc-linux-gnu
-DCMAKE_SYSTEM_PREFIX_PATH:PATH=/usr/x86_64-pc-linux-gnu
-DCMAKE_INSTALL_LIBDIR:STRING=lib
-DCMAKE_INSTALL_DATAROOTDIR:PATH=/usr/share/
-DINCLUDE_INSTALL_DIR=/usr/x86_64-pc-linux-gnu/include/jsoncpp
-DBUILD_SHARED_LIBS:BOOL=TRUE
-DJSONCPP_WITH_CMAKE_PACKAGE:BOOL=TRUE
-DJSONCPP_WITH_POST_BUILD_UNITTEST:BOOL=FALSE
-DJSONCPP_WITH_WARNING_AS_ERROR:BOOL=FALSE
-DJSONCPP_WITH_TESTS=TRUE

This allows us to natively cross compile, e.g. x86_64 lands in /usr/x86_64-pc-linux-gnu, i686 in /usr/i686-pc-linux-gnu and so on.

[zorun]

Ok, so you just need to build with -DINCLUDE_INSTALL_DIR=include/jsoncpp instead (this is now relative to CMAKE_INSTALL_PREFIX). By the way, jsoncpp automatically adds a directory called json, so you would end up with headers in /usr/x86_64-pc-linux-gnu/include/jsoncpp/json/. But that was probably already the case with 1.7.2.

By the way, you have the same problem I had, which is that libdir is a relative path in 1.7.3. If you try to compile a program that uses pkg-config to find jsoncpp 1.7.3, it will fail to compile.

@cdunn2001 maybe it's worth mentioning in the release notes that people customizing these variables (probably distribution packagers) may need to change absolute paths into relative paths?

[tgurr]

I've a problem setting -DINCLUDE_INSTALL_DIR=include/jsoncpp since when I do that I get a CMake error:

-- JsonCpp Version: 1.7.4
-- Found PythonInterp: /usr/bin/python2 (found suitable version "2.7.11", minimum required is "2.6") 
-- Configuring done
-- Generating done
CMake Error in src/lib_json/CMakeLists.txt:
  Target "jsoncpp_lib" INTERFACE_INCLUDE_DIRECTORIES property contains path:

    "/var/tmp/paludis/build/dev-libs-jsoncpp-1.7.4/work/build/include/jsoncpp"

  which is prefixed in the build directory.

About /usr/x86_64-pc-linux-gnu/include/jsoncpp/json/ you're correct, we're doing this on purpose to avoid conflicts with the json-c package.

[cdunn2001]

We need you both to come to an agreement. I am not an expert on cmake and would rather not take this decision myself.

[zorun]

Yes, I tried to work this out, but I'm no expert on cmake either.

@tgurr as a workaround, you can patch INCLUDE_INSTALL_DIR in the main CMakeLists.txt. For some reason, changing this variable in the file instead of passing it as an option to cmake avoids the runtime error.

[anatol]

What is recommended solution for this problem? Is it something that is going to be fixed in jsoncpp build script?

[ppaalanen]

On Gentoo, installed jsoncpp 1.7.7, and the pc-file looks like this:

prefix=/usr
exec_prefix=${prefix}
libdir=${exec_prefix}/lib64
includedir=${prefix}//usr/include/jsoncpp

Which leads to -I/usr/usr/include/jsoncpp which is wrong.

The build script looks like this: https://gitweb.gentoo.org/repo/gentoo.git/tree/dev-libs/jsoncpp/jsoncpp-1.7.7.ebuild

Are you saying that this is a distribution error and they should fix INCLUDE_INSTALL_DIR?

[zorun]

The build script you link to says:

# Follow Debian, Ubuntu, Arch convention for headers location
# bug #452234
-DINCLUDE_INSTALL_DIR="${EPREFIX}"/usr/include/jsoncpp

But Archlinux installs headers in /usr/include/json (which seems to be the default), not /usr/include/jsoncpp. The build script does not use INCLUDE_INSTALL_DIR at all: https://git.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/jsoncpp

From what I see here in the CMake documentation this variable should probably be relative, not absolute.

[ppaalanen]

@zorun I actually tried to patch the INCLUDE_INSTALL_DIR to be relative, but then cmake itself fails as described in the comment by @tgurr .
Note that installing to /usr/include is not possible, as there are several packages that would all provide the files in /usr/include/json and conflict, hence the jsoncpp must be added in the path.

How can we have both a correct .pc file and install the headers into a directory named by the package to avoid conflicts?

[SoapGentoo]

With my pull request (#562), this issue is solved now in Gentoo, as GNUInstallDirs is supposed to be used with relative paths. I believe this issue can be closed now.

[tgurr]

Thanks! 1.8.0 works for me as well (passing -DCMAKE_INSTALL_INCLUDEDIR=include/jsoncpp results in a correct pkg-config file).

[zorun]

Thanks a lot for the fix @SoapGentoo ! It still works fine for Arch Linux.