bash-4.4# pkg-config --list-all | grep ruby
ruby-2.5          Ruby - Object Oriented Script Language

bash-4.4# pkg-config --list-all            
libpcre16         libpcre16 - PCRE - Perl compatible regular expressions C library with 16 bit character support
tic               tic - ncurses 6.1 add-on library
libpq             libpq - PostgreSQL libpq library
python            Python - Python library
ncurses           ncurses - ncurses 6.1 library
libecpg           libecpg - PostgreSQL libecpg library
json              json-c - A JSON implementation in C
popt              popt - popt library.
geoip             geoip - A non-DNS IP-to-country resolver library.
menu              menu - ncurses 6.1 add-on library
libpcreposix      libpcreposix - PCREPosix - Posix compatible interface to libpcre
ruby-2.5          Ruby - Object Oriented Script Language
ncursesw          ncursesw - ncurses 6.1 library
ncurses++         ncurses++ - ncurses 6.1 add-on library
odbccr            unixODBC - unixODBC is an Open Source ODBC sub-system.
rpm               RPM - RPM Package Manager
jansson           Jansson - Library for encoding, decoding and manipulating JSON data
ncurses++w        ncurses++w - ncurses 6.1 add-on library
odbcinst          unixODBC - unixODBC is an Open Source ODBC sub-system.
panelw            panelw - ncurses 6.1 add-on library
libcurl           libcurl - Library to transfer files with ftp, http, etc.
libevent_core     libevent_core - libevent_core
libmemcached      libmemcached - libmemcached C/C++ library.
libsasl2          Cyrus SASL - Cyrus SASL implementation
hiredis           hiredis - Minimalistic C client library for Redis.
tinfo             tinfo - ncurses 6.1 terminal interface library
openssl           OpenSSL - Secure Sockets Layer and cryptography libraries and tools
lua5.3            Lua 5.3 - An Extensible Extension Language
panel             panel - ncurses 6.1 add-on library
libevent_openssl  libevent_openssl - libevent_openssl adds openssl-based TLS support to libevent
sqlite3           SQLite - SQL database engine
libcrypto         OpenSSL-libcrypto - OpenSSL cryptography library
libpcrecpp        libpcrecpp - PCRECPP - C++ wrapper for PCRE
libevent_extra    libevent_extra - libevent_extra
expat             expat - expat XML parser
libssl            OpenSSL-libssl - Secure Sockets Layer and cryptography libraries
libpcre           libpcre - PCRE - Perl compatible regular expressions C library with 8 bit character support
lua               Lua 5.3 - An Extensible Extension Language
json-c            json-c - A JSON implementation in C
libecpg_compat    libecpg_compat - PostgreSQL libecpg_compat library
libpgtypes        libpgtypes - PostgreSQL libpgtypes library
udev              udev - udev
systemd           systemd - systemd System and Service Manager
odbc              unixODBC - unixODBC is an Open Source ODBC sub-system.
libevent          libevent - libevent is an asynchronous notification event loop library
liblzma           liblzma - General purpose data compression library
zlib              zlib - zlib compression library
libevent_pthreads libevent_pthreads - libevent_pthreads adds pthreads-based threading support to libevent
uuid              uuid - Universally unique id library
menuw             menuw - ncurses 6.1 add-on library
form              form - ncurses 6.1 add-on library
libmnl            libmnl - Minimalistic Netlink communication library
libxml-2.0        libXML - libXML library version2.
python2           Python - Python library
formw             formw - ncurses 6.1 add-on library
python-2.7        Python - Python library