pkg/55645: cairo does not find fontconfig in NetBSD-current

[martin%NetBSD.org@localhost]

>Number:         55645
>Category:       pkg
>Synopsis:       cairo does not find fontconfig in NetBSD-current
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Sep 07 11:35:00 +0000 2020
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.72
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD whoever-brings-the-night.aprisoft.de 9.99.72 NetBSD 9.99.72 (WHOEVER) #347: Tue Sep 1 17:22:18 CEST 2020 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/sparc64/compile/WHOEVER sparc64
Architecture: sparc64
Machine: sparc64
>Description:

Trying to build cairo from pkgsrc-current on a netbsd-current with all
dependencies up to date fails:

checking whether cairo's PNG functions feature could be enabled... yes
checking for cairo's EGL functions feature... 
checking whether cairo's EGL functions feature could be enabled... no (not required by any backend)
checking for cairo's GLX functions feature... 
checking whether cairo's GLX functions feature could be enabled... no (not required by any backend)
checking for cairo's WGL functions feature... 
checking whether cairo's WGL functions feature could be enabled... no (not required by any backend)
checking for cairo's script surface backend feature... 
checking whether cairo's script surface backend feature could be enabled... yes
checking for cairo's FreeType font backend feature... 
checking for FREETYPE... yes
checking whether cairo's FreeType font backend feature could be enabled... yes
checking for cairo's Fontconfig font backend feature... 
checking for FONTCONFIG... no
checking whether cairo's Fontconfig font backend feature could be enabled... no (requires fontconfig >= 2.2.95)
configure: error:  Fontconfig font backend feature could not be enabled
*** Error code 1

The buildlink3 step did not link /usr/X11R7/lib/pkgconfig/fontconfig.pc
into the .buildlink dir. USE_BUILTIN.fontconfig is YES (according to
PKG_DEBUG_LEVEL=2 output) and it seems the list of pc files to copy
is usually generated by "pkg_info -f fontconfig", but for the builtin
case ${_BLNK_PKG_INFO.${_pkg_}} is set to true, so we end up with

	true -f fontconfig | .... | sort -u | while read ...

I have no idea how this is supposed to work or why it now fails for me
but seems to work for others.

>How-To-Repeat:

Update your netbsd system to current, remove all outdated pkgs, and
try to build graphics/cairo.

>Fix:
n/a