PHP: PECL installations not functioning

When attempting to install a new PECL module (hash – I want to test the new features in it), I get the following output:

# pecl install hash
WARNING: running in safe mode requires that all files created be the same uid as the current script.  PHP reports this script is uid: 0, and current user is: root
downloading hash-1.1.tgz ...
Starting to download hash-1.1.tgz (100,713 bytes)
......................done: 100,713 bytes
30 source files, building

Warning: putenv(): Safe Mode warning: Cannot set environment variable 'PATH' - it's not in the allowed list in PEAR/Builder.php on line 272
running: phpize
Configuring for:
PHP Api Version:         20020918
Zend Module Api No:      20020429
Zend Extension Api No:   20021010
building in /var/tmp/pear-build-root/hash-1.1
running: /tmp/tmpTEbiPB/hash-1.1/configure
sh: /usr/bin/configure: No such file or directory
ERROR: `/tmp/tmpTEbiPB/hash-1.1/configure' failed

I’ve not been able to find anything that covers this online. Suggestions?