Pathname#inspect on Ruby 2.0 throws away the encoding of the object's
underlying string and returns a string tagged as ASCII-8BIT.
If you simply write
puts Pathname.new("some string with non-ascii bytes").inspect
no error will be raised, because the implementation of Pathname#inspect
does not call into Object#inspect.
However, if you wrap that pathname object in an array first, then
puts [Pathname.new("some string with non-ascii bytes")].inspect
will raise Encoding::CompatibilityError: "inspected result must be ASCII
only or use the same encoding with default external".
Raising an error in this codepath is new in Ruby 2.0, and this specific
bug is fixed in Ruby 2.1. I've opened a bug upstream:
https://bugs.ruby-lang.org/issues/9915FixesHomebrew/homebrew#29947.
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