Auto merge of #4408 - bundler:seg-enotsup, r=segiddins

[SharedHelpers] Handle Errno::ENOTSUP in .filesystem_access

Closes #4394.

\c @RochesterinNYC

lib/bundler/errors.rb

@@ -107,4 +107,12 @@ def message
 
     status_code(27)
   end
+
+  class OperationNotSupportedError < PermissionError
+    def message
+      "Attempting to #{action} `#{@path}` is unsupported by your OS."
+    end
+
+    status_code(28)
+  end
 end

lib/bundler/shared_helpers.rb

@@ -109,6 +109,8 @@ def filesystem_access(path, action = :write)
       raise TemporaryResourceError.new(path, action)
     rescue Errno::EPROTO
       raise VirtualProtocolError.new
+    rescue Errno::ENOTSUP
+      raise OperationNotSupportedError.new(path, action)
     end
 
     def const_get_safely(constant_name, namespace)

spec/bundler/shared_helpers_spec.rb

@@ -369,6 +369,15 @@
           Bundler::VirtualProtocolError)
       end
     end
+
+    context "system throws Errno::ENOTSUP" do
+      let(:file_op_block) { proc {|_path| raise Errno::ENOTSUP } }
+
+      it "raises a OperationNotSupportedError" do
+        expect { subject.filesystem_access("/path", &file_op_block) }.to raise_error(
+          Bundler::OperationNotSupportedError)
+      end
+    end
   end
 
   describe "#const_get_safely" do