Of course, you can always specify an absolute path name for a file--for example:

env = Environment()
env.Program('prog', ['main.c', '/usr/joe/lib/foo1.c', 'foo2.c'])
       

Which, when executed, would yield:

% scons -Q
cc -o src/prog/foo2.o -c src/prog/foo2.c
cc -o src/prog/main.o -c src/prog/main.c
cc -o /usr/joe/lib/foo1.o -c /usr/joe/lib/foo1.c
cc -o src/prog/prog src/prog/main.o /usr/joe/lib/foo1.o src/prog/foo2.o

(As was the case with top-relative path names, notice that the /usr/joe/lib/foo1.o object file is built in the same directory as its source file. See Chapter 15, Separating Source and Build Trees: Variant Directories, below, for information about how to build the object file in a different subdirectory.)