F = T ∇ Sτ

C printf() function doesn't flush buffers by default, and a lot of code using it may miss this, therefore creating interactivity problems to the end user. It's not specific to C though - it's about the standard I/O streams, and the problem may appear anywhere. The post is based on StackExchange discussion, so you can dig deeper if you want:  Turn off buffering in pipe .

Xcode build locations may mislead developers hoping to fully control the output of the IDE. While we can use CONFIGURATION_BUILD_DIR for the xcodebuild tool during continuous integration, IDE generates files in different locations, and sometimes we want to control it too.