Issue #9578 has been reported by Dmitry Medvinsky.

----------------------------------------
Bug #9578: unctionundeclared in readline.c
https://bugs.ruby-lang.org/issues/9578

* Author: Dmitry Medvinsky
* Status: Open
* Priority: Normal
* Assignee: 
* Category: ext
* Target version: 
* ruby -v: 2.0.0p353 (2013-11-22 revision 43784) [x86_64-linux]
* Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
When compiling Ruby 2.1.1, I get the following error

<pre>
make[2]: Entering directory '/tmp/ruby-build.20140228114849.30108/ruby-2.1.1/ext/readline'
compiling readline.c
readline.c: In function °∆Init_readline°«:
readline.c:1977:26: error: °∆Function°« undeclared (first usen this function)
     rl_pre_input_hook = (Function *)readline_pre_input_hook;
                          ^
readline.c:1977:26: note: each undeclared identifier is reported only once for each function it appears in
readline.c:1977:36: error: expected expression before °∆)°« token
     rl_pre_input_hook = (Function *)readline_pre_input_hook;
                                    ^
readline.c: At top level:
readline.c:634:1: warning: °∆readline_pre_input_hook°« defined but not used [-Wunused-function]
 readline_pre_input_hook(void)
 ^
Makefile:228: recipe for target 'readline.o' failed
make[2]: *** [readline.o] Error 1
make[2]: Leaving directory '/tmp/ruby-build.20140228114849.30108/ruby-2.1.1/ext/readline'
exts.mk:198: recipe for target 'ext/readline/all' failed
make[1]: *** [ext/readline/all] Error 2
</pre>

Readline version:

    /* Hex-encoded Readline version number. */
    #define RL_READLINE_VERSION     0x0603          /* Readline 6.3 */
    #define RL_VERSION_MAJOR        6
    #define RL_VERSION_MINOR        3
    
    ...
    
    extern rl_hook_func_t *rl_pre_input_hook;

OS version:

    Linux 3.13.5-1-ARCH #1 SMP PREEMPT Sun Feb 23 00:25:24 CET 2014 x86_64 GNU/Linux

I can provide full `configure` and `make` logs, if required.



-- 
http://bugs.ruby-lang.org/