Checking for freetype2 configura erro ao instalar o PHP 5.6.37 do AUR

Question

Estou tentando instalar a versão 5.6.37 do PHP AUR usando o comando makepkg -i , mas quando chega ao momento de verificar o "freetype2", exibe o erro:

checking for freetype2... configure: error: freetype-config not found.

Eu já tenho o 7.2 instalado, mas preciso do 5.6 para um projeto mais antigo, e como no Ubuntu, pretendo ter ambos instalados.

makepkg -i
==> Making package: php56 5.6.37-1 (Wed 12 Sep 2018 12:27:39 PM +08)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
  -> Found php-5.6.37.tar.xz
  -> Found php-5.6.37.tar.xz.asc
  -> Found php.ini.patch
  -> Found apache.conf
  -> Found php-fpm.conf.in.patch
  -> Found logrotate.d.php-fpm
  -> Found php-fpm.service
  -> Found php-fpm.tmpfiles
  -> Found use-enchant2.patch
  -> Found php-freetype-2.9.1.patch
==> Validating source files with sha512sums...

[...]

checking whether to enable truetype string function in GD... yes
checking whether to enable JIS-mapped Japanese font support in GD... no
If configure fails try --with-vpx-dir=<DIR>
checking for jpeg_read_header in -ljpeg... yes
checking for png_write_image in -lpng... yes
checking for XpmFreeXpmImage in -lXpm... yes
checking for pkg-config... (cached) no
checking for freetype2... configure: error: freetype-config not found.
==> ERROR: A failure occurred in build().
    Aborting...

Instalar freetype2 com Pacman não resolveu isso.