Error building curl with c-ares via pkgconfig #2203
Description
I did this
PKG_CONFIG_PATH=/opt/WP/common.libs/lib/pkgconfig ./configure --enable-ares
I expected the following
curl will build
what happened
configure script exited with error:
checking that c-ares is good and recent enough... no
configure: error: c-ares library defective or too old
config.log:
configure:40149: checking that c-ares is good and recent enough
configure:40176: gcc -o conftest -Werror-implicit-function-declaration -O2 -Wno-system-headers conftest.c -lcares -lz >&5
conftest.c:257:18: fatal error: ares.h: No such file or directory
#include <ares.h>
^
compilation terminated.
ares.h was not found
c-ares is not installed in default install path, because it was built with --prefix but pkgconfig should deliver that custom path, because libcares.pc includes includedir=/opt/WP/common.libs/include:
# cat /opt/WP/common.libs/lib/pkgconfig/libcares.pc
#***************************************************************************
# Project ___ __ _ _ __ ___ ___
# / __|____ / _` | '__/ _ \/ __|
# | (_|_____| (_| | | | __/\__ \
# \___| \__,_|_| \___||___/
#
prefix=/opt/WP/common.libs
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include
Name: c-ares
URL: http://daniel.haxx.se/projects/c-ares/
Description: asynchronous DNS lookup library
Version: -
Requires:
Requires.private:
Cflags: -I${includedir} -DCARES_STATICLIB
Libs: -L${libdir} -lcares
Libs.private:
and to confirm that ares.h exists in that path:
# ll /opt/WP/common.libs/include/ares.h
-rw-r--r-- 1 root root 23253 Nov 29 14:01 /opt/WP/common.libs/include/ares.h
It's not a critical issue, because I can build curl with:
CPPFLAGS=-I/opt/WP/common.libs/include LDFLAGS=-L/opt/WP/common.libs/lib ./configure --enable-ares
(config.log then looks like this:)
configure:40149: checking that c-ares is good and recent enough
configure:40176: gcc -o conftest -Werror-implicit-function-declaration -O2 -Wno-system-headers -isystem /opt/WP/common.libs/include -L/opt/WP/common.libs/lib conftest.c -lcares -lz >&5
configure:40176: $? = 0
configure:40178: result: yes
but I'd like to use pkgconfig in the future.
operating system
curl-7.56.1
c-ares-1.13.0
CentOS Linux release 7.4.1708 (Core)