[Reproducible-builds] Bug#794270: FTBFS: oniguruma.h: error: conflicting types for 'OnigUChar'

[Chris West (Faux)]

Source: ruby-mkrf
Version: 0.2.3+dfsg-5
Severity: serious
Tags: sid
Justification: fails to build from source
User: reproducible-builds at lists.alioth.debian.org
Usertags: ftbfs

Dear Maintainer,

The package fails to build:

In file included from /usr/include/ruby-2.1.0/ruby/encoding.h:23:0,
                 from /usr/include/ruby-2.1.0/ruby/io.h:24,
                 from /usr/include/ruby-2.1.0/ruby/backward/rubyio.h:6,
                 from libxml.h:17,
                 from libxml.c:5:
/usr/include/ruby-2.1.0/ruby/oniguruma.h:108:15: error: conflicting types for 'OnigUChar'
 #define UChar OnigUChar
               ^
/usr/include/ruby-2.1.0/ruby/oniguruma.h:111:24: note: previous declaration of 'OnigUChar' was here
 typedef unsigned char  OnigUChar;
                        ^
rake aborted!
Command failed with status (1): [gcc -fPIC -g -O2 -fstack-protector-strong ...]

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/ruby-mkrf.html

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.19.0-23-generic (SMP w/8 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)