This problem is probably caused because PECL is installing the header files to a location different from the one that is used during the installation of phpredis. You can confirm this by looking at the console messages.
$> sudo pecl install igbinary
Build process completed successfully Installing
'/usr/lib/php/extensions/no-debug-non-zts-20090626/igbinary.so'
Installing '/usr/include/php/ext/igbinary/igbinary.h'
$> ./configure --enable-redis-igbinary
checking for PHP installed headers prefix... /usr/local/include/php
checking if debug is enabled... no checking if zts is enabled... no
checking for re2c... re2c checking for re2c version... 0.13.5 (ok)
checking for gawk... gawk checking whether to enable redis support...
yes, shared checking whether to enable sessions... yes checking
whether to enable igbinary serializer support... yes checking for
igbinary includes... configure: error: Cannot find igbinary.h
Just move the igbinary folder to the correct location:
$> cp /usr/include/php/ext/igbinary /usr/local/include/php/ext/igbinary -fr
And it should correctly find the igbinary header file:
checking whether to enable igbinary serializer support... yes
checking for igbinary includes... /usr/local/include/php