We recently went through a lot of trouble trying to diagnose a customer problem with a custom plugin. The customer was just copying/pasting our official documentation, which turns out is wrong. We need to validate all of our published code examples:
1) make sure they build without warnings/errors
2) make sure they use the latest API functions
3) make sure they actually work as intended
4) create a Makefile to use that will have a high warning level, and will check all of the functions used - something like -z defs

One of the problems the customer had was that they were using the wrong function name (because of the erroneous documentation). The function was not defined, and the compiler only gave a warning (if any). Either the warning should be a hard error, or we need to tell the linker to give an error (like ld -z defs).