Bug 684280

Summary:	dev-cpp/nlohmann_json should provide cmake config files
Product:	Gentoo Linux	Reporter:	Nicolas Werner <nicolas.werner>
Component:	Current packages	Assignee:	Gentoo Media-video project <media-video>
Status:	RESOLVED FIXED
Severity:	normal
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Nicolas Werner 2019-04-24 16:18:51 UTC

Current versions of nlohmann_json are built with meson instead of the upstream default CMake. Because of this, the ebuild doesn't install the following files:

/usr/lib64/cmake/nlohmann_json/nlohmann_jsonConfig.cmake
/usr/lib64/cmake/nlohmann_json/nlohmann_jsonTargets.cmake
/usr/lib64/cmake/nlohmann_json/nlohmann_jsonConfigVersion.cmake

Because of this packages using the system nlohmann_json and building via CMake, that are using the recommended way to integrate nlohmann_json into a CMake project, fail to build, because they can't find it. To work around this issue requires patching every ebuild to use pkgconfig to find it, which is not really practical.

The proper solution would be in my opinion to build nlohmann_json via CMake and not via meson as, as far as I can tell, the meson build files are only supplied for easier integration with meson packages when used via mesons wrap system. I don't know however, if meson packages or other build systems can still find it, if it is installed via CMake, as I don't know, if CMake also provides a *.pc file. Meson probably should work, as it does have compatibility with CMake find_package files.

Comment 1 Larry the Git Cow gentoo-dev

2019-06-28 23:26:10 UTC

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=0682016ae2e1edbdfa11c73ce44cd0f981a91a0e

commit 0682016ae2e1edbdfa11c73ce44cd0f981a91a0e
Author:     Tim Harder <radhermit@gentoo.org>
AuthorDate: 2019-06-28 23:21:41 +0000
Commit:     Tim Harder <radhermit@gentoo.org>
CommitDate: 2019-06-28 23:24:48 +0000

    dev-cpp/nlohmann_json: install non-amalgamated headers
    
    Also, use cmake for building instead of meson.
    
    Closes: https://bugs.gentoo.org/684280
    
    Signed-off-by: Tim Harder <radhermit@gentoo.org>

 .../nlohmann_json/nlohmann_json-3.6.1-r1.ebuild    | 44 ++++++++++++++++++++++
 1 file changed, 44 insertions(+)