__init__.py 
foo/bar runfiles/foo/bar
testäα𝐴🐈'.txt /runfiles/testäα𝐴🐈'.txt
target-with-space /runfiles/with space\and backslash
 target-with-newline /runfiles/with\nnewline\band backslash
 source\swith\sspace,\nnewline,\band\sbackslash /runfiles/with space,\nnewline,\band backslash
