Issue #1157 has been updated by Michael Lang.


I encountered the same error when installing to a fresh copy of Ubuntu 8.10 Intrepid Ibex.  Turned out ext/zlib has extconf.rb which means its make files get generated from calling "ruby extconf.rb" 

Since there was no ruby interpreter installed, the extconf.rb files couldn't be executed.  Solution:

./configure
make
sudo make install

# repeat
./configure
make 
sudo make install
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