Failed to build smtp module on CentOS 7

[olegrok]

#27 203.7 [ 66%] Building C object smtp/CMakeFiles/lib.dir/smtpc.c.o
#27 203.7 /tmp/luarocks_smtp-0.0.5-1-kgB1u4/smtp/smtp/smtpc.c: In function ‘check_libcurl_protocol’:
#27 203.7 /tmp/luarocks_smtp-0.0.5-1-kgB1u4/smtp/smtp/smtpc.c:103:2: error: ‘for’ loop initial declarations are only allowed in C99 mode
#27 203.7   for (const char * const *p = info->protocols; *p != NULL; ++p) {
#27 203.7   ^
#27 203.7 /tmp/luarocks_smtp-0.0.5-1-kgB1u4/smtp/smtp/smtpc.c:103:2: note: use option -std=c99 or -std=gnu99 to compile your code
#27 203.7 gmake[2]: *** [smtp/CMakeFiles/lib.dir/smtpc.c.o] Error 1
#27 203.7 gmake[1]: *** [smtp/CMakeFiles/lib.dir/all] Error 2
#27 203.7 gmake: *** [all] Error 2
#27 203.7 
#27 203.7 Error: Failed installing dependency: http://rocks.tarantool.org/smtp-0.0.5-1.rockspec - Build error: Failed building.
#27 211.1    ⨯ Failed to install rocks: Failed to run 
#27 211.1 /opt/tarantool-enterprise/tarantoolctl rocks make

[Totktonada]

$ docker run -it centos:7
[root@b5dc13f9efe1 /]# yum install -y gcc
[root@b5dc13f9efe1 /]# gcc --version | head -n 1
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)

The problem is quite similar to tarantool/small#25.

[olegrok]

And there was the same problem in tuple-merger tarantool/tuple-merger@489ac0e

[djorem]

I have the same problem.

[Totktonada]

I'll merge Oleg's PR and make release 0.0.6 a bit sooner today.