1.4.0 Installs pkgconfig and cmake files into wrong locations

[yurivict]

Before they were installed into:
``
lib/cmake/nanoflann/nanoflannConfig.cmake
lib/cmake/nanoflann/nanoflannConfigVersion.cmake
lib/cmake/nanoflann/nanoflannTargets.cmake
libdata/pkgconfig/nanoflann.pc

Now they are installed into:

share/cmake/nanoflann/nanoflannConfig.cmake
share/cmake/nanoflann/nanoflannConfigVersion.cmake
share/cmake/nanoflann/nanoflannTargets.cmake
share/pkgconfig/nanoflann.pc

pkg-config doesn't find nanoflann. cmake files that are installed by nanoflann into share/cmake are the only application specifix cmake files there, so this appears to be a wrong location too.

[jlblancoc]

You're right, it seems e.g. from https://packages.ubuntu.com/jammy/all/libeigen3-dev/filelist
That the order of subdirectories should be swapped.

I'll provide a fix and release again, or feel free to propose a PR !

[jlblancoc]

For the records: I changed it from lib to share since that's the more appropriate path for a headers only lib

[yurivict]

Yes, please release again. Thanks!

[jlblancoc]

v1.4.1 has been verified to correctly provide working cmake and pkgconfig files. There are now two examples with the two build systems under examples/*.

[yurivict]

1.4.1 installs .pc file into share/pkgconfig/nanoflann.pc where pkg-config isn't looking.

$ ls /usr/local/share/pkgconfig/
nanoflann.pc
$ pkg-config --cflags nanoflann
Package nanoflann was not found in the pkg-config search path.
Perhaps you should add the directory containing `nanoflann.pc'
to the PKG_CONFIG_PATH environment variable
Package 'nanoflann', required by 'virtual:world', not found

.pc files should be in libdata/pkgconfig/.

[jlblancoc]

Mmm... in which distribution is that?
I tested it (on an Ubuntu 20.04), and:

$ sudo make install
...
Install the project...
-- Install configuration: ""
-- Up-to-date: /usr/local/share/nanoflann/cmake/nanoflannTargets.cmake
-- Up-to-date: /usr/local/share/pkgconfig/nanoflann.pc
-- Up-to-date: /usr/local/share/nanoflann/cmake/nanoflannConfig.cmake
-- Up-to-date: /usr/local/share/nanoflann/cmake/nanoflannConfigVersion.cmake
-- Up-to-date: /usr/local/include/nanoflann.hpp

$ pkg-config nanoflann --cflags
-I/usr/local/include

Just to make sure it's that .pc file the one pkg-config saw:

$ sudo make uninstall
-- Uninstalling "/usr/local/share/nanoflann/cmake/nanoflannTargets.cmake"
-- Uninstalling "/usr/local/share/pkgconfig/nanoflann.pc"
-- Uninstalling "/usr/local/share/nanoflann/cmake/nanoflannConfig.cmake"
-- Uninstalling "/usr/local/share/nanoflann/cmake/nanoflannConfigVersion.cmake"
-- Uninstalling "/usr/local/include/nanoflann.hpp"

$ pkg-config nanoflann --cflags
Package nanoflann was not found in the pkg-config search path.
No package 'nanoflann' found

??

[jlblancoc]

Stupid question... FreeBSD :-)

Could you check where does the well-known library eigen3 install its .pc file in that distribution?

In Debian-based ones, architecture-independent files go into share, arch-dependent into lib, that's why it makes more sense to install this headers-only library on the former...

[yurivict]

FreeBSD 13, but I don't think this matters.

share/pkgconfig/ is not where .pc files are installed.
Why did you move it from libdata/pkgconfig/?

[yurivict]

Eigen installs it here: /usr/local/libdata/pkgconfig/eigen3.pc

[jlblancoc]

Ah, I think I see the issue (I still would compare to eigen3, which is a "reference" headers-only library used by many):

• The default from cmake, per se, is not "/libdata", but it's added via CMAKE_FLAGS in the ports repo for eigen3:
  https://cgit.freebsd.org/ports/tree/math/eigen3/Makefile#n15
• Also for eigen3, the "*.cmake" files are in the datadir, see first lines here: https://cgit.freebsd.org/ports/tree/math/eigen3/pkg-plist

So, I think that with:

• this commit a12946e ,
• adding CMAKE_ARGS= -DPKGCONFIG_INSTALL_DIR:PATH="libdata/pkgconfig" to math/nanoflann/Makefile
• Perhaps adding %%DATADIR%% to PLIST_FILES ??

will work for FreeBSD, w/o breaking existing policies in other distros...
Do you agree?

[yurivict]

Why don't you just bring back the previous .pc location libdata/pkgconfig/ ?

[jlblancoc]

It's weird: according to pkgconfig docs,

1.1. Search paths
By default, pkg-config will search for modules installing data files in two directories: one for the architecture-specific modules,
that is installed in a sub-directory of the libdir (usually /usr/lib/pkgconfig), and one for non-architecture specific modules, that
can be shared among multiple architectures (usually /usr/share/pkgconfig).

the /usr/share/pkgconfig should work too and would be preferred for non-architecture specific...

But if it causes problems in that distribution, I could roll back it for the .pc file; I think cmake being "smarter" and more up-to-date shouldn't have any problems to locate its own stuff under /usr/share/nanoflann/cmake/*.cmake

[jlblancoc]

Closed (again XD) by fa97cab

Will release again soon, after some further time for testing.