嘗試在 上安裝多個 gem cygwin，我不斷收到此錯誤：/usr/share/ruby/2.2.0/mkmf.rb:456:in try_do': The compiler failed to generate an executable file. (RuntimeError)
此錯誤是以下完整錯誤訊息的一部分：
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/usr/bin/ruby.exe -r ./siteconf20150603-27012-w371hi.rb extconf.rb
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
[...truncated...]
--without-pkg-config
/usr/share/ruby/2.2.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /usr/share/ruby/2.2.0/mkmf.rb:541:in `try_link0'
from /usr/share/ruby/2.2.0/mkmf.rb:556:in `try_link'
from /usr/share/ruby/2.2.0/mkmf.rb:637:in `try_ldflags'
from /usr/share/ruby/2.2.0/mkmf.rb:1780:in `pkg_config'
from extconf.rb:15:in `<main>'
extconf failed, exit code 1
Gem files will remain installed in /cygdrive/d/d/.gem/ruby/gems/ffi-1.9.8 for inspection.
Results logged to /cygdrive/d/d/.gem/ruby/extensions/x86_64-cygwin/ffi-1.9.8/gem_make.out
我嘗試了在谷歌上可以找到的所有東西，其中一些確實有效，包括：
- 透過cygwin setup安裝gem對應的cygwin包
- 安裝更多 cygwin 軟體包，取決於失敗的 gem
但對於這個非常具體的例子，我找不到缺少的東西......
答案1
此錯誤的解決方案是（並且適用於所有此類錯誤）查看文件mkmf.log（對我來說/cygdrive/d/d/Documents/.gem/ruby/extensions/x86_64-cygwin/ffi-1.9.8/mkmf.log）並查看缺少哪些庫。
就我而言，-lcrypt和-lgmp都失敗了，所以我不得不“cygwin-setup”libcrypt-devel和libgmp-devel.