test_generate_bin_bindir_with_user_install_warning(TestGemInstaller) fails on windows.
The test fails on Windows with the following error:
@@ -1 +1,3 @@
+"WARNING: You don't have C:\Windows in your PATH,
+\t gem executables will not run.
The problem is incorrect test in Gem::Installer.check_that_user_bin_dir_is_in_path()
It splits PATH by File::PATH_SEPARATOR and checks if the bin dir is included in this array.
But file system is case-insensitive on Windows (and may be case-insensitive on OS X too),
so it is incorrect way to compare these paths as string.
So, I suggest to compare them using File.identical? which should work correctly on any file system.