Issue #13538 has been reported by znz (Kazuhiro NISHIYAMA).

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Bug #13538: head: illegal option -- c
https://bugs.ruby-lang.org/issues/13538

* Author: znz (Kazuhiro NISHIYAMA)
* Status: Open
* Priority: Normal
* Assignee: znz (Kazuhiro NISHIYAMA)
* Target version: 
* ruby -v: ruby 2.5.0dev (2017-05-02 trunk 58541) [i386-solaris2.11]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
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[Solaris 11.3でビルドを試した](http://blog.n-z.jp/blog/2017-05-02-ruby-sample.html)ところ、configure の最後で以下のようなエラーが出ました。

    ---
    Configuration summary for ruby version 2.5.0
    
    head: illegal option -- c
    usage: head [-n #] [-#] [filename...]
    /export/home/vagrant/opt/ruby
    head: illegal option -- c
    usage: head [-n #] [-#] [filename...]
    ${prefix}
    head: illegal option -- c
    (略)
	head: illegal option -- c
    usage: head [-n #] [-#] [filename...]
    yes
    head: illegal option -- c
    usage: head [-n #] [-#] [filename...]
    man
    
    ---

head -c は [POSIX](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/head.html) になくて、代わりの手段を探してみたところ、[どの環境でも使えるシェルスクリプトを書くためのメモ ver4.51 - Qiita の headコマンド](http://qiita.com/richmikan@github/items/bd4b21cf1fe503ab2e5c#head%E3%82%B3%E3%83%9E%E3%83%B3%E3%83%89) にあったので `head -c26` を `dd bs=1 count=26 2>/dev/null` に書き換えます。




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