I was trying to build the Poco library when I got this error:
/home/blah/someplace/poco-poco-1.4.6p4-release/build/rules/global:62: *** Current working directory not under $PROJECT_BASE. Stop. make: Leaving directory
The same code had built successfully on another computer, so I knew there was nothing wrong.
Turns out that this error is actually caused if the path where you have unzipped Poco has a symlink in it. The
someplace directory above was actually a symbolic link. Once I copied Poco to a path which had no symlink, it compiled fine.