OS ver : centos 7

sw ver: 2.0 branch

build steps:

 ./autogen.sh
 ./configure
 make
 make install

expect results : no error

actual results :

`configure: error: Package requirements (libpcre) were not met:

No package 'libpcre' 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 DEPS_CFLAGS
and DEPS_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.`