pkg/48919: fonts/fontconfig fails to build

[sighoya%gmail.com@localhost]

>Number:         48919
>Category:       pkg
>Synopsis:       fonts/fontconfig fails to build
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 17 13:45:00 +0000 2014
>Originator:     Philip
>Release:        current
>Organization:
>Environment:
System: Linux phantom 3.14.6-1-ARCH #1 SMP PREEMPT Sun Jun 8 10:08:38 CEST 2014 
x86_64 GNU/Linux

>Description:
checking for FREETYPE... no
configure: error: Package requirements (freetype2) were not met:

Package 'libpng', required by 'freetype2', not found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables FREETYPE_CFLAGS
and FREETYPE_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
*** Error code 1

... But I have png and freetype2 installed:
pkg_info | grep 'freetype2\|png'
freetype2-2.5.3nb1  Font rendering engine and library API
png-1.6.12          Library for manipulating PNG images

>How-To-Repeat:
cd $PKGSRC/fonts/fontconfig && bmake

>Fix: