0.0.6 build fails for ruby 1.8.7 with gcc 4.8.2

[jhoblitt]

I've been unable to build 0.0.6 (or any earlier version) on Fedora 20 for ruby 1.8.7 with gcc 4.8.2. gcc 4.8.2 + ruby 2.0.0 builds as expected. I used a Gentoo box and was able to get 0.0.6 to build for ruby 1.8.7 using gcc 4.7.2.

gcc version (fedora 20):

$ gcc -v
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.8.2/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin --enable-initfini-array --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-isl=/builddir/build/BUILD/gcc-4.8.2-20131212/obj-x86_64-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.8.2-20131212/obj-x86_64-redhat-linux/cloog-install --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.8.2 20131212 (Red Hat 4.8.2-7) (GCC) 

Build error:

Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /home/jhoblitt/.rvm/rubies/ruby-1.8.7-p374/bin/ruby extconf.rb 
checking for main() in -lstdc++... yes
checking for ruby/encoding.h... yes
creating Makefile
CXX is automatically set to g++

make
g++ -I. -I. -I/home/jhoblitt/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/1.8/x86_64-linux -I. -DHAVE_RUBY_ENCODING_H    -fPIC -O2 -fno-tree-dce -fno-optimize-sibling-calls  -fPIC    -c unf.cc
In file included from unf.cc:5:0:
/usr/include/ruby/encoding.h:102:68: error: expected identifier before numeric constant
 PRINTF_ARGS(VALUE rb_enc_sprintf(rb_encoding *, const char*, ...), 2, 3);
                                                                    ^
/usr/include/ruby/encoding.h:102:68: error: expected ‘,’ or ‘...’ before numeric constant
/usr/include/ruby/encoding.h:102:73: error: expected constructor, destructor, or type conversion before ‘;’ token
 PRINTF_ARGS(VALUE rb_enc_sprintf(rb_encoding *, const char*, ...), 2, 3);
                                                                         ^
/usr/include/ruby/encoding.h:115:99: error: expected identifier before numeric constant
 PRINTF_ARGS(NORETURN(void rb_enc_raise(rb_encoding *, VALUE, const char*, ...)), 3, 4);
                                                                                                   ^
/usr/include/ruby/encoding.h:115:99: error: expected ‘,’ or ‘...’ before numeric constant
/usr/include/ruby/encoding.h:115:104: error: expected constructor, destructor, or type conversion before ‘;’ token
 PRINTF_ARGS(NORETURN(void rb_enc_raise(rb_encoding *, VALUE, const char*, ...)), 3, 4);
                                                                                                        ^
In file included from unf.cc:5:0:
/usr/include/ruby/encoding.h:216:65: error: declaration of C function ‘long int rb_memsearch(const void*, long int, const void*, long int, rb_encoding*)’ conflicts with
 long rb_memsearch(const void*,long,const void*,long,rb_encoding*);
                                                                 ^
In file included from /home/jhoblitt/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/1.8/x86_64-linux/ruby.h:756:0,
                 from unf.cc:3:
/home/jhoblitt/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/1.8/x86_64-linux/intern.h:387:6: error: previous declaration ‘long int rb_memsearch(const void*, long int, const void*, long int)’ here
 long rb_memsearch _((const void*,long,const void*,long));
      ^
make: *** [unf.o] Error 1


Gem files will remain installed in /home/jhoblitt/github/puppetlabs-concat/.bundle/ruby/1.8/gems/unf_ext-0.0.6 for inspection.
Results logged to /home/jhoblitt/github/puppetlabs-concat/.bundle/ruby/1.8/gems/unf_ext-0.0.6/ext/unf_ext/gem_make.out
An error occurred while installing unf_ext (0.0.6), and Bundler cannot continue.
Make sure that `gem install unf_ext -v '0.0.6'` succeeds before bundling.

[knu]

Sorry for replying too late. It looks like the compiler is using header files for ruby >=1.9, because ruby/encoding.h first appeared in ruby 1.9.1. I know the ruby-devel package inappropriately installs the header files directly under the system include directory, and it didn't get a fix before its EOL. You either need to temporarily uninstall ruby-devel or specify --with-opt-include=/path/to/ruby/1.8/headers, I suppose.