尝试在我的Ubuntu 14.04上安装ruby2d gem时出现以下错误
Building native extensions. This could take a while...
ERROR: Error installing ruby2d:
ERROR: Failed to build gem native extension.
/home/rishi/.rvm/rubies/ruby-2.2.1/bin/ruby -r ./siteconf20160401-21057-yotffi.rb extconf.rb
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling ruby2d.c
ruby2d.c: In function ‘render’:
ruby2d.c:133:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
for (int i = 0; i < num_objects; ++i) {
^
ruby2d.c:133:3: note: use option -std=c99 or -std=gnu99 to compile your code
ruby2d.c:215:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
struct image_data *data;
^
ruby2d.c:234:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
struct text_data *data;
^
ruby2d.c: In function ‘ruby2d_show’:
ruby2d.c:253:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
char *title = RSTRING_PTR(rb_iv_get(self, "@title"));
^
make: *** [ruby2d.o] Error 1
make failed, exit code 2
Gem files will remain installed in /home/rishi/.rvm/gems/ruby-2.2.1/gems/ruby2d-0.2.0 for inspection.
Results logged to /home/rishi/.rvm/gems/ruby-2.2.1/extensions/x86_64-linux/2.2.0/ruby2d-0.2.0/gem_make.out
如果有人能给我一些建议，那就太好了！
P.S。我已按照simple2d GitHub Page
上的所有步骤，在我的机器中成功安装了simple2d gem
提前致谢：）