Encoding error details

encoding_discovery.rb

str = "ó bhí mé óg, thaitin leabhair liom"                                      
bytes = str.bytes                                                               
                                                                                
targets = ["贸","铆","茅","贸"].uniq                                            
                                                                                
p :original, str                                                                
w = str.force_encoding('ISO-8859-1')                                            
                                                                                
#p :iso88591, w                                                                 
#p :utf8,w.encode("UTF-8")                                                      
#p :utf16,w.encode("UTF-16")                                                    
p bytes.pack('c*').force_encoding('UTF-8')                                      
Encoding.name_list.each do |enc|                                                
  encoded = bytes.pack('c*').force_encoding(enc).encode('UTF-8') rescue ""      
  if targets.all?{|t| encoded.include?(t)}                                      
    p [encoded, enc]                                                            
  end                                                                           
end   

results.txt

:original
"ó bhí mé óg, thaitin leabhair liom"
"ó bhí mé óg, thaitin leabhair liom"
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "GB2312"]
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "GB18030"]
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "GBK"]
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "EUC-CN"]
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "eucCN"]
["贸 bh铆 m茅 贸g, thaitin leabhair liom", "CP936"]