we don't install ruby at RbConfig.ruby on buildenv

Author: sorah

test/ruby/test_m17n_comb.rb

@@ -731,10 +731,7 @@ def test_str_count
 
   def test_str_crypt
     begin
-      # glibc 2.16 or later denies salt contained other than [0-9A-Za-z./] #7312
-      glibcpath = `ldd #{RbConfig.ruby}`[/\S+\/libc.so\S+/]
-      glibcver = `#{glibcpath}`[/\AGNU C Library.*version ([0-9.]+)/, 1].split('.').map(&:to_i)
-      strict_crypt = (glibcver <=> [2, 16]) > -1
+      strict_crypt = true
     rescue
     end