$ wget https://pkg-config.freedesktop.org/releases/pkg-config-0.29.2.tar.gz
$ tar xvf pkg-config-0.29.2.tar.gz
$ cd pkg-config-0.29.2/
$ mkdir build
$ cd build
$ ../configure --prefix=/opt/pkg-config/0.29.2 --with-internal-glib
$ make
$ make install