When emerging net-libs/nghttp2-1.18.0 in the configuration step I got the next error: configure: Package libcares was not found in the pkg-config search path. Perhaps you should add the directory containing `libcares.pc' to the PKG_CONFIG_PATH environment variable Package 'libcares', required by 'world', not found configure: error: applications were requested (--enable-app) but dependencies are not met. -- It seems that it's necessary to install "net-dns/c-ares".
David's way helps me. It works! Thank you! 1+
When the "utils" local USE flag is enabled, =net-libs/nghttp2-1.18* has a build and run-time dependency on >=net-dns/c-ares-1.7.5. The "utils" USE flag causes --enable-app to be passed to ./configure, triggering the dependencies. I see the same thing as David in my config.log. Additionally, this line jumped out at me, hence the minimum version: configure: $PKG_CONFIG --exists --print-errors "libcares >= 1.7.5" A check of installed binaries/libraries shows that /usr/bin/nghttpx, installed when "utils" is enabled, links against libcares.so.2, making this a definite run-time dep as well. FWIW, /usr/bin/nghttpx is the only file in the package which links to that library, at least on my system. The ebuild simply needs >=net-dns/c-ares-1.7.5 added to the utils?() conditional in RDEPEND to fix this. Or one can just do what David said for the really quick fix. :-)
Created a pull request to resolve the issue for both the 1.18.1 and the 9999 ebuild - https://github.com/gentoo/gentoo/pull/3553
And now a pull request with less "git commit -s -a"... <sigh> https://github.com/gentoo/gentoo/pull/3554
*** Bug 605468 has been marked as a duplicate of this bug. ***
thanks, merged here: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=31ba7a6956054e40b599f58bf71eb4eba1811211
