ketmar, I understand that GDC documentation can be as terse as it wants to be, especially in the man page, which is supposed to be the shortest, for quick command line reference. It still seems a little odd to me that there wouldn't be additional instructions somewhere in the introductory pages to D on the D Wiki or somewhere else conveniently linked, on compiling multiple input files that are applicable to GDC or to all three compilers, rather than just specific to DMD on Windows.
There's a joke in mathematics that sometimes a hard, unsolved problem is passed over in a paper with the words "the rest is left as an exercise for the reader." Leaving the subtleties of multiple file GDC usage as an exercise, whatever those may be for D, if any, is certainly better than omitting language documentation or development or bugfixes, and also better than not having multiple compilers to choose from. So on reflection, I agree with leaving multiple file command line GDC usage as an exercise for anyone who wants to do it, in order to conserve limited development resources for improving more important things about D. So I'm sorry about all the fuss. I would delete the thread if I could. I understand that you're implying multiple file compilation should go smoothly the same for D as it does for any other GCC supported language, without any particular difficulties for D that you've seen about it, and I hope it goes smoothly for me as well.