On OS X, sys_get_tmp_dir() returns /var/private/..., which really is below /private/var.
merged branch webfactory/fix-finder-test-osx (PR #7536)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #7536).

Discussion
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Fix Finder tests on OS X

... where sys_get_temp_dir() does not return a realpath().

Commits
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0ed8441 On OS X, sys_get_tmp_dir() returns /var/private/..., which really is below /private/var.