Handle ENXIO when /dev/tty cannot be opened

JRuby 9.4 seems to have trouble opening /dev/tty on Linux, so we
fall back on stderr output and a hard raise to kill the build.

Author: headius

extconf.rb

@@ -11,20 +11,27 @@
     WARNING: See https://github.com/rbenv/ruby-build/pull/2517 for more details.
   MSG
 
+  # write a dummy makefile so no executable is built
+  File.write("Makefile", dummy_makefile($srcdir).join(""))
+
   # extconf.rb runs in a captured subprocess, so the only way to output is via /dev/tty
-  if File.exist?("/dev/tty") && File.writable?("/dev/tty")
-    error << <<~MSG
-      WARNING:
-      WARNING: The native jruby executable has not been installed.
-    MSG
-    File.write("/dev/tty", error)
-  else
-    # /dev/tty is not available, so write to stderr and raise
-    $stderr.write(error)
-    raise
+  begin
+    if File.exist?("/dev/tty") && File.writable?("/dev/tty")
+      long_error = error + <<~MSG
+        WARNING:
+        WARNING: The native jruby executable has not been installed.
+      MSG
+      File.write("/dev/tty", long_error)
+      return
+    end
+  rescue Errno::ENXIO
+    # JRuby versions prior to 10 can't always open /dev/tty
+    # Ignore and fail the install below
   end
-  File.write("Makefile", dummy_makefile($srcdir).join(""))
-  return
+
+  # /dev/tty is not available, so write to stderr and raise
+  $stderr.write(error)
+  raise Errno::ENOENT, "jruby.sh"
 end
 
 # jruby.sh exists, proceed to build