Use of C99 breaks gem install on CentOS 7

[tas50]

This gem uses C99 code that prevents the gem install on CentOS 7 unless people use pull in the backported development tools. Is there any way to use older style code here that would compile on CentOS 7 out of the box?

       Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
       
       current directory:
       /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/io-wait-0.2.1/ext/io/wait
       /opt/chef/embedded/bin/ruby -I /opt/chef/embedded/lib/ruby/3.0.0 -r
       ./siteconf20220209-187-few2km.rb extconf.rb
       checking for rb_io_wait()... yes
       checking for sys/ioctl.h... yes
       checking for FIONREAD in sys/ioctl.h,sys/ioctl.h... yes
       creating Makefile
       
       current directory:
       /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/io-wait-0.2.1/ext/io/wait
       make DESTDIR\\= clean
       
       current directory:
       /opt/chef/embedded/lib/ruby/gems/3.0.0/gems/io-wait-0.2.1/ext/io/wait
       make DESTDIR\\=
       compiling wait.c
       wait.c: In function 'io_wait':
       wait.c:332:2: error: 'for' loop initial declarations are only allowed in C99
       mode
         for (int i = 0; i < argc; i += 1) {
         ^
       wait.c:332:2: note: use option -std=c99 or -std=gnu99 to compile your code
       make: *** [wait.o] Error 1
       
       make failed, exit code 2

[johnmccrae]

This also breaks on Windows with the same error message. Specifically Windows 11 but will assume it happens on other contemporary versions as well.

[XrXr]

Your compiler should support C99 since it prompted you about it. Try compiling in C99 mode when installing:

gem install io-wait --version 0.2.1 -- --with-cflags=-std=c99