Failed to build iconv gem on ruby 1.9.2

Question

I fail to install the 'iconv' gem, because of weird build errors.
I have build the 'libiconv' from source and linked the .h and .dylib into the rvm's include and lib directory. When I run

gem install iconv

Gem outputs strange build errors:

Building native extensions. This could take a while...

ERROR:  Error installing iconv:
    ERROR: Failed to build gem native extension.

/Users/myusername/.rvm/rubies/ruby-1.9.2-rc2/bin/ruby extconf.rb
checking for iconv() in iconv.h... no
checking for iconv() in -liconv... yes
checking for const of iconv() 2nd argument... no
creating Makefile

make
gcc -I. -I/Users/myusername/.rvm/rubies/ruby-1.9.2-rc2/include/ruby-1.9.1/x86_64-darwin10.4.0 -I/Users/myusername/.rvm/rubies/ruby-1.9.2-rc2/include/ruby-1.9.1/ruby/backward -I/Users/myusername/.rvm/rubies/ruby-1.9.2-rc2/include/ruby-1.9.1 -I. -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE   -fno-common -O3 -ggdb -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers -Wshorten-64-to-32 -Wno-long-long  -fno-common -pipe  -o iconv.o -c iconv.c
In file included from iconv.c:21:
/Users/myusername/.rvm/rubies/ruby-1.9.2-rc2/include/ruby-1.9.1/ruby/backward/st.h:2:2: warning: #warning use "ruby/st.h" instead of bare "st.h"
iconv.c:22:20: error: intern.h: No such file or directory
iconv.c: In function ‘map_charset’:
iconv.c:139: error: ‘struct RHash’ has no member named ‘tbl’
iconv.c:139: error: ‘struct RHash’ has no member named ‘tbl’
iconv.c:142: error: ‘struct RHash’ has no member named ‘tbl’
iconv.c: In function ‘iconv_create’:
iconv.c:187: error: ‘struct RString’ has no member named ‘len’
iconv.c:188: error: ‘struct RString’ has no member named ‘len’
iconv.c:190: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:190: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:190: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:190: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:192: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:193: error: ‘struct RString’ has no member named ‘len’
iconv.c: In function ‘iconv_fail’:
iconv.c:328: error: ‘struct RString’ has no member named ‘len’
iconv.c: In function ‘iconv_fail_retry’:
iconv.c:352: error: ‘ruby_errinfo’ undeclared (first use in this function)
iconv.c:352: error: (Each undeclared identifier is reported only once
iconv.c:352: error: for each function it appears in.)
iconv.c: In function ‘rb_str_derive’:
iconv.c:371: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:371: error: ‘struct RString’ has no member named ‘len’
iconv.c:373: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:373: error: ‘struct RString’ has no member named ‘len’
iconv.c:374: error: ‘struct RString’ has no member named ‘ptr’
iconv.c: In function ‘iconv_convert’:
iconv.c:418: error: ‘struct RArray’ has no member named ‘len’
iconv.c:418: error: ‘struct RArray’ has no member named ‘ptr’
iconv.c:436: error: ‘struct RString’ has no member named ‘len’
iconv.c:437: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:455: warning: comparison of unsigned expression >= 0 is always true
iconv.c:458: warning: comparison between signed and unsigned
iconv.c:459: warning: comparison between signed and unsigned
iconv.c:491: warning: implicit conversion shortens 64-bit value into a 32-bit value
iconv.c:494: warning: implicit conversion shortens 64-bit value into a 32-bit value
iconv.c:497: error: ‘struct RArray’ has no member named ‘len’
iconv.c:498: error: ‘struct RArray’ has no member named ‘ptr’
iconv.c:499: error: ‘struct RArray’ has no member named ‘ptr’
iconv.c:501: error: ‘struct RString’ has no member named ‘len’
iconv.c:502: error: ‘struct RString’ has no member named ‘ptr’
iconv.c:514: warning: implicit conversion shortens 64-bit value into a 32-bit value
iconv.c: In function ‘iconv_s_convert’:
iconv.c:615: error: ‘struct RString’ has no member named ‘len’
make: *** [iconv.o] Error 1


Gem files will remain installed in /Users/myusername/.rvm/gems/ruby-1.9.2-rc2/gems/iconv-0.1 for inspection.
Results logged to /Users/myusername/.rvm/gems/ruby-1.9.2-rc2/gems/iconv-0.1/ext/iconv/gem_make.out

How do I make it install and build properly.

Thanks

Answer 1

For what it's worth - I was able to build 1.9.2 p136 using RVM and linking to libiconv I installed with Homebrew. This allowed me to use the JSON gem without problems. I wrote a quick blog post about it here: http://www.v25media.com/blog/read/forcing_ruby_1_9_2_via_rvm_to_use_iconv but the gist of it is:

$ brew install libiconv
$ rvm remove 1.9.2
$ rvm install 1.9.2 --with-iconv-dir=/usr/local/Cellar/libiconv/1.13.1