OS X::10.6 - configure: error: C compiler cannot create executables

Ran into this trying to compile Apache Httpd:

Configuring Apache Portable Runtime Utility library...

checking for APR-util... yes
checking for gcc... gcc
checking for C compiler default output file name...
configure: error: in `/Users/bkarels/devtools/httpd-2.2.17':
configure: error: C compiler cannot create executables
See `config.log' for more details.

Mac OS X solution:

Go back to: Snow Leopard DVD > Optional Installs > Xcode.mpkg:

Option: System Tools > Checked
Option: UNIX Dev Support > Checked <-- Important

Run installer. No reboot necessary. Compiler commands execute as expected.

Credit to solution author kevinx.
Original thread from discussions.apple.com: can be found here.