Heroku 1.5.6 depends explicitly on json 1.1.0 about legacy-cli HOT 4 CLOSED

Heroku 1.5.6 now fails to build json on my Vista Home Premium (SP2) using RubyInstaller RC1 with the MinGW-based DevKit which generally enables windows users to compile native C-based extensions.

C:>ruby --version
ruby 1.9.1p243 (2009-07-16 revision 24175) [i386-mingw32]

C:>gem --version
1.3.5

C:\Users\Jon\Documents>gem update
Updating installed gems
Updating heroku
Building native extensions. This could take a while...
ERROR: Error installing heroku:
ERROR: Failed to build gem native extension.

C:/ruby19/bin/ruby.exe extconf.rb
creating Makefile

make
gcc -Wall -I. -IC:/ruby19/include/ruby-1.9.1/i386-mingw32 -I/C/ruby19/include/ruby-1.9.1/ruby/backward -I/C/ruby19/include/ruby-1.9.1 -I. -O2 -g -Wall -Wno-parentheses -o parser.o -c parser.c
parser.rl:4:16: re.h: No such file or directory
In file included from parser.rl:5:
c:/ruby19/include/ruby-1.9.1/ruby/backward/st.h:2:2: warning: #warning use "ruby/st.h" instead of bare "st.h"
parser.rl: In function cParser_initialize': parser.rl:460: error: structure has no member namedtbl'
make: *** [parser.o] Error 1

Gem files will remain installed in C:/ruby19/lib/ruby/gems/1.9.1/gems/json-1.1.0 for inspection.
Results logged to C:/ruby19/lib/ruby/gems/1.9.1/gems/json-1.1.0/ext/json/ext/parser/gem_make.out

from legacy-cli.

FWIW, I have json 1.2.0 and json_pure 1.2.0 installed on my system...likely from a successful heroku 1.5.2 install

from legacy-cli.

Please fix this issue, heroku worked fine with ruby 1.9 before.
What was the incentive behind locking the gem dependencies versions? If you're afraid of API changes you could use a range of versions instead of a fixed version.

from legacy-cli.

Fixed in 1.6.3 and above.

from legacy-cli.