Issue #10079 has been reported by Gustavo Frederico Temple Pedrosa.

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Bug #10079: Warnings in definition of macro 'PACKED_STRUCT'
https://bugs.ruby-lang.org/issues/10079

* Author: Gustavo Frederico Temple Pedrosa
* Status: Open
* Priority: High
* Assignee: Nobuyoshi Nakada
* Category: build
* Target version: current: 2.2.0
* ruby -v: ruby 2.2.0dev (2014-07-21 trunk 46893) [powerpc64le-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
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After the commit db433dc39d07449184a908d417919e3de8b70405, the building shows many warnings like below:

~~~
compiling pty.c
In file included from pty.c:1:0:
../.././include/ruby/io.h:54:30: warning: 'packed' attribute ignored [-Wattributes]
 PACKED_STRUCT(typedef struct {
                              ^
../../.ext/include/powerpc64le-linux/ruby/config.h:71:26: note: in definition of macro 'PACKED_STRUCT'
 #define PACKED_STRUCT(x) x __attribute__((packed))
                          ^
~~~



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