gistfile1.txt

$ ruby  extconf.rb 
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/usr/local/rbenv/versions/2.6.6/bin/$(RUBY_BASE_NAME)
        --with-ssl-dir
        --without-ssl-dir
        --with-ssl-include
        --without-ssl-include=${ssl-dir}/include
        --with-ssl-lib
        --without-ssl-lib=${ssl-dir}/lib
        --with-openssl-config
        --without-openssl-config
        --with-pkg-config
        --without-pkg-config
Traceback (most recent call last):
        6: from extconf.rb:92:in `<main>'
        5: from extconf.rb:65:in `pkg_config_wrapper'
        4: from /usr/local/rbenv/versions/2.6.6/lib/ruby/2.6.0/mkmf.rb:1832:in `pkg_config'
        3: from /usr/local/rbenv/versions/2.6.6/lib/ruby/2.6.0/mkmf.rb:672:in `try_ldflags'
        2: from /usr/local/rbenv/versions/2.6.6/lib/ruby/2.6.0/mkmf.rb:570:in `try_link'
        1: from /usr/local/rbenv/versions/2.6.6/lib/ruby/2.6.0/mkmf.rb:552:in `try_link0'
/usr/local/rbenv/versions/2.6.6/lib/ruby/2.6.0/mkmf.rb:467:in `try_do': The compiler failed to generate an executable file. (RuntimeError)