Fails to find Libxc

[jinzx10]

Details

The following error [Could NOT find Libxc (missing: Libxc_INCLUDE_DIRS] appears since #3623

I'm using Ubuntu 22.04 on WSL2. The libxc package (libxc-dev) was installed via apt. The shared object and header are located at

/usr/lib/x86_64-linux-gnu/libxc.so
/usr/include/xc.h

Compilation with libxc has no issue prior to #3623 . Can anyone give some advice?

Have you read FAQ on the online manual http://abacus.deepmodeling.com/en/latest/community/faq.html

• Yes, I have read the FAQ part on online manual.

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[WHUweiqingzhou]

@caic99 could you have a look?

[caic99]

@caic99 could you have a look?

@yizeyi18 Could you please take a look? Thanks!

[yizeyi18]

Hi zx:
In /usr/lib/x86_64-linux-gnu/pkgconfig, there would be a file libxc.pc, and have contents like below:

prefix=/opt/libxc-6.2.2
exec_prefix=${prefix}
libdir=${prefix}/lib
includedir=${prefix}/include
Name: libxc

Description: Library of exchange and correlation functionals to be used in DFT codes
Requires:
Version: 6.2.2
Libs: -L${libdir} -lxc
Cflags: -I${includedir}

May you show what is in your libxc.pc?

Also, after a configure failure, a CMakeCache.txt would in your build directory. May you show what does grep Libxc CMakeCache.txt output in your build directory?
It should contain lines like that:

Libxc_CFLAGS:INTERNAL=-I/opt/libxc-6.2.2/include
Libxc_CFLAGS_I:INTERNAL=
Libxc_CFLAGS_OTHER:INTERNAL=
Libxc_FOUND:INTERNAL=1
Libxc_INCLUDEDIR:INTERNAL=/opt/libxc-6.2.2/include
Libxc_INCLUDE_DIRS:INTERNAL=/opt/libxc-6.2.2/include
Libxc_LDFLAGS:INTERNAL=-L/opt/libxc-6.2.2/lib;-lxc
Libxc_LDFLAGS_OTHER:INTERNAL=
Libxc_LIBDIR:INTERNAL=/opt/libxc-6.2.2/lib
Libxc_LIBRARIES:INTERNAL=xc
Libxc_LIBRARY_DIRS:INTERNAL=/opt/libxc-6.2.2/lib
Libxc_LIBS:INTERNAL=

[jinzx10]

Hi @yizeyi18 , here's my libxc.pc:

prefix=/usr
exec_prefix=/usr
libdir=/usr/lib/x86_64-linux-gnu
includedir=/usr/include

Name: libxc
Description: Library of exchange and correlation functionals to be used in DFT codes
Requires:
Version: 5.1.7
Libs: -L${libdir} -lxc
Cflags: -I${includedir}

and here's the output of grep 'Libxc' CMakeCache.txt:

pkgcfg_lib_Libxc_xc:FILEPATH=/usr/lib/x86_64-linux-gnu/libxc.so
Libxc_CFLAGS:INTERNAL=
Libxc_CFLAGS_I:INTERNAL=
Libxc_CFLAGS_OTHER:INTERNAL=
Libxc_FOUND:INTERNAL=1
Libxc_INCLUDEDIR:INTERNAL=/usr/include
Libxc_INCLUDE_DIRS:INTERNAL=
Libxc_LDFLAGS:INTERNAL=-L/usr/lib/x86_64-linux-gnu;-lxc
Libxc_LDFLAGS_OTHER:INTERNAL=
Libxc_LIBDIR:INTERNAL=/usr/lib/x86_64-linux-gnu
Libxc_LIBRARIES:INTERNAL=xc
Libxc_LIBRARY_DIRS:INTERNAL=/usr/lib/x86_64-linux-gnu
Libxc_LIBS:INTERNAL=
Libxc_LIBS_L:INTERNAL=
Libxc_LIBS_OTHER:INTERNAL=
Libxc_LIBS_PATHS:INTERNAL=
Libxc_MODULE_NAME:INTERNAL=libxc
Libxc_PREFIX:INTERNAL=/usr
Libxc_STATIC_CFLAGS:INTERNAL=
Libxc_STATIC_CFLAGS_I:INTERNAL=
Libxc_STATIC_CFLAGS_OTHER:INTERNAL=
Libxc_STATIC_INCLUDE_DIRS:INTERNAL=
Libxc_STATIC_LDFLAGS:INTERNAL=-L/usr/lib/x86_64-linux-gnu;-lxc
Libxc_STATIC_LDFLAGS_OTHER:INTERNAL=
Libxc_STATIC_LIBDIR:INTERNAL=
Libxc_STATIC_LIBRARIES:INTERNAL=xc
Libxc_STATIC_LIBRARY_DIRS:INTERNAL=/usr/lib/x86_64-linux-gnu
Libxc_STATIC_LIBS:INTERNAL=
Libxc_STATIC_LIBS_L:INTERNAL=
Libxc_STATIC_LIBS_OTHER:INTERNAL=
Libxc_STATIC_LIBS_PATHS:INTERNAL=
Libxc_VERSION:INTERNAL=5.1.7
Libxc_libxc_INCLUDEDIR:INTERNAL=
Libxc_libxc_LIBDIR:INTERNAL=
Libxc_libxc_PREFIX:INTERNAL=
Libxc_libxc_VERSION:INTERNAL=
__pkg_config_checked_Libxc:INTERNAL=1
//ADVANCED property for variable: pkgcfg_lib_Libxc_xc
pkgcfg_lib_Libxc_xc-ADVANCED:INTERNAL=1

[yizeyi18]

and here's the output of grep 'Libxc' CMakeCache.txt:

Libxc_CFLAGS:INTERNAL=
Libxc_CFLAGS_I:INTERNAL=
Libxc_CFLAGS_OTHER:INTERNAL=
Libxc_FOUND:INTERNAL=1
Libxc_INCLUDEDIR:INTERNAL=/usr/include
Libxc_INCLUDE_DIRS:INTERNAL=

Libxc_FOUND, but no Libxc_INCLUDE_DIRS, nor Libxc_CFLAGS...? Quite strange.
As a quick fix, you could try this patch: quick.patch
It may take some time to detect what's wrong here.

[jinzx10]

and here's the output of grep 'Libxc' CMakeCache.txt:

Libxc_CFLAGS:INTERNAL=
Libxc_CFLAGS_I:INTERNAL=
Libxc_CFLAGS_OTHER:INTERNAL=
Libxc_FOUND:INTERNAL=1
Libxc_INCLUDEDIR:INTERNAL=/usr/include
Libxc_INCLUDE_DIRS:INTERNAL=

Libxc_FOUND, but no Libxc_INCLUDE_DIRS, nor Libxc_CFLAGS...? Quite strange. As a quick fix, you could try this patch: quick.patch It may take some time to detect what's wrong here.

The patch works! Thank you very much :)

[yizeyi18]

Hi zx:
I propose the problem comes like that: the output var Libxc_INCLUDE_DIRS is empty because pkg-config filters /usr/include out, as pkg_search_module relies. This do not affect compile process but crashes cmake's find_package_handle_standard_args.
According to this, I made the PR above, runs on my pc. May you take a look?

Debug output of pkg-config

$ pkg-config --debug --cflags libxc
Error printing enabled by default due to use of output options besides --exists, --atleast/exact/max-version or --list-all. Value of --silence-errors: 0
Error printing enabled
Adding virtual 'pkg-config' package to list of known packages
Looking for package 'libxc'
Looking for package 'libxc-uninstalled'
Reading 'libxc' from file '/usr/lib/x86_64-linux-gnu/pkgconfig/libxc.pc'
Parsing package file '/usr/lib/x86_64-linux-gnu/pkgconfig/libxc.pc'
  line>prefix=/usr
 Variable declaration, 'prefix' has value '/usr'
  line>exec_prefix=/usr
 Variable declaration, 'exec_prefix' has value '/usr'
  line>libdir=/usr/lib/x86_64-linux-gnu
 Variable declaration, 'libdir' has value '/usr/lib/x86_64-linux-gnu'
  line>includedir=/usr/include
 Variable declaration, 'includedir' has value '/usr/include'
  line>
  line>Name: libxc
  line>Description: Library of exchange and correlation functionals to be used in DFT codes
  line>Requires:
  line>Version: 5.1.7
  line>Libs: -L${libdir} -lxc
  line>Cflags: -I${includedir}
Path position of 'libxc' is 5
Adding 'libxc' to list of known packages
Package libxc has -I/usr/include in Cflags
Removing -I/usr/include from cflags for libxc
Package libxc has -L /usr/lib/x86_64-linux-gnu in Libs
Removing -L /usr/lib/x86_64-linux-gnu from libs for libxc
 post-recurse: libxc
adding CFLAGS_OTHER string ""
 post-recurse: libxc
 original: libxc
   sorted: libxc
adding CFLAGS_I string ""
returning flags string ""

@jinzx10 @caic99

[jinzx10]

Hi @yizeyi18 ,
Thanks for the explanation! I just checked out #3771 and it indeed solves my issue. I think this issue can be closed alongside the merge of #3771 . @caic99