In Java Project "Build Required Projects" checkbox
has different meaning -- it forces building of
projects only on compile classpath (which could be
a subset of required projects).
Have java project "App" which has java library
project "DataModel" on its compile classpath.
Have java library project "Utils" which is on
DataModel's compile classpath.
Both libraries are in required projects of App,
but building of Utils depends on DataModel setting
of checkbox "Build Req.Proj." not on the App's one.
It should be probably renamed to something more
appropriate (like "Directly Required Projects"?) .
This was resolved as part of issue 47507. The checkbox was moved to
compilation panel and renamed to "Build Projects on Classpath".
*** This issue has been marked as a duplicate of 47507 ***