"external macro implementation type could not be found for macro"

Using Swift
1

I have a project which uses several macros and which builds just fine inside Xcode, but when building via command line I get the error "external macro implementation type ... could not be found for macro" for all macro packages. Both seem to use the same Swift toolchains. So, why should there be a difference, and how could I resolve this?

2

UPDATE: I switched from the toolchain currently used in Xcode (6.2) to the newer 6.2.4 in the command line (via swiftly). Now it also builds from the command line. It is unclear to me if this has something to do with a problem in the older 6.2 or if this has something to do with a clear start without old caches or the like (I did remove the .build folder before, that did not resolve it).