How to update Ruby in Google SketchUp? - ruby

Question

Currently Google SketchUp for Mac has Ruby version 1.8.5 which I find a bit outdated. I can update Ruby to 1.8.7 (OSX's version) by the following commands
$ cd /Applications/Google\ SketchUp\ 7/SketchUp.app/Contents/Frameworks/Ruby.framework/Versions/Current
$ ls
Headers/ Resources/ Ruby
$ ls Headers/
config.h defines.h intern.h missing.h ruby.h
$ rm -r Headers
$ ln -s /System/Library/Frameworks/Ruby.framework/Headers
$ ln -fs /System/Library/Frameworks/Ruby.framework/Ruby
SketchUp starts without a problem and Ruby console shows version 1.8.7.
1.9.2
Now I try to go further and update to 1.9.2-rc2. Google SketchUp requires i386 binary, which can be produced by the following commands
$ cd ~/ruby-1.9.2-rc2/
$ ARCHFLAGS="-arch i386" CFLAGS="-arch i386" LDFLAGS="-arch i386" ./configure --with-arch=i386
$ make && sudo make install
Then I copy the necessary files to SketchUp:
$ cd /Applications/Google\ SketchUp\ 7/SketchUp.app/Contents/Frameworks/Ruby.framework/
$ rm Headers Ruby
$ cp /usr/local/bin/ruby Ruby
$ mkdir Headers
$ cp /usr/local/include/ruby-1.9.1/i386-darwin10.4.0/ruby/config.h Headers/
$ cp /usr/local/include/ruby-1.9.1/ruby.h Headers/
$ cp -r /usr/local/include/ruby-1.9.1/ruby/* Headers/
$ ls Headers
backward/ defines.h dl.h intern.h missing.h re.h ruby.h util.h vm.h
config.h digest.h encoding.h io.h oniguruma.h regex.h st.h version.h
and when I try to start SketchUp I get the following error report
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Dyld Error Message:
Library not loaded: #executable_path/../Frameworks/Ruby.framework/Versions/A/Ruby
Referenced from: /Applications/Google SketchUp 7/SketchUp.app/Contents/MacOS/SketchUp
Reason: no suitable image found. Did find:
/Applications/Google SketchUp 7/SketchUp.app/Contents/MacOS/../Frameworks/Ruby.framework/Versions/A/Ruby: can't map
/Applications/Google SketchUp 7/SketchUp.app/Contents/MacOS/../Frameworks/Ruby.framework/Versions/A/Ruby: can't map
/usr/local/lib/Ruby: not a file
/usr/lib/Ruby: not a file
Model: MacBookPro7,1, BootROM MBP71.0039.B05, 2 processors, Intel Core 2 Duo, 2.4 GHz, 4 GB, SMC 1.62f5
Could you tell me why?
UPDATE1
Dan Rathbun made some tests and found the following
On Win32 when I tried to get Sketchup
to load any 1.9.x I got an "Entry
point not found" for the ruby C
function "rb_set_kcode" which is no
longer in 1.9.x (it was renamed, and
the Ruby people did not alias the old
name to the new name.)
Basically Sketchup calls rb_set_kcode
to set the character encoding to UTF8
just after loading the Ruby
interpreter. It works fine for any
Ruby in the 1.8.x branch, but in 1.9.x
the Ruby project totally reengineered
the character encoding, and gave all
the C functions new identifiers, and
added alot more functions.
The solution for 1.9.x and Sketchup
seems to be that Sketchup needs to be
"Ruby Version Agile", which means a
coding change by the Google Guys in
Boulder.

Answer 1

The C level API has changed in 1.9.1. Notice that the paths to gems indicate the API compatibility: .../1.8/... for the 1.8 line and .../1.9.1/... for the 1.9.2 line.
This makes it very difficult to upgrade without recompiling.
You can require "backports"; this will get you the most of the new methods of 1.9.x, but not the new syntax or the string encoding.