error log current directory: /Users//.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/ffi-1.15.0/ext/ffi\_c /Users//.rbenv/versions/2.6.6/bin/ruby -I /Users//.rbenv/versions/2.6.6/lib/ruby/2.6.0 -r ./siteconf20210405-41671-1rcq3m7.rb extconf.rb checking for ffi\_prep\_closure\_loc() in -lffi... yes checking for ffi\_prep\_cif\_var()... yes checking for ffi\_raw\_call()... yes checking for ffi\_pre..