执行'bundle install'时出现此错误:
..........
Installing libxml-ruby (2.7.0)
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/home/ubuntu/.rvm/rubies/ruby-1.8.7-p374/bin/ruby extconf.rb
checking for socket() in -lsocket... no
checking for gethostbyname() in -lnsl... yes
checking for atan() in -lm... no
checking for atan() in -lm... yes
checking for inflate() in -lz... yes
checking for iconv_open() in -liconv... no
checking for libiconv_open() in -liconv... no
checking for libiconv_open() in -llibiconv... no
checking for iconv_open() in -llibiconv... no
checking for iconv_open() in -lc... yes
checking for xmlParseDoc() in …