req-compile does not handle stdin paths correctly

[nat45928]

When following docs for compiling a group of projects I get the following exception (using req-compile as an example package):

(.venv) C:\repos\req-compile>req-candidates --paths-only | req-compile -v
INFO:req_compile.metadata:Extracting metadata for C:\repos\req-compile
DEBUG:req_compile.metadata:Extracting directly from a source directory
INFO:req_compile.metadata:Attempting to fetch metadata from setup.py
DEBUG:req_compile.metadata:Setting root to C:\Users\NATHAN~1\AppData\Local\Temp\tmpuyi0wfb9_NonExtractor_req-compile
INFO:req_compile.metadata:Parsing setup.py setup.py
INFO:req_compile.metadata:Parsing from setup.cfg
Traceback (most recent call last):
  File "C:\repos\req-compile\.venv\Scripts\req-compile-script.py", line 11, in <module>
    load_entry_point('req-compile', 'console_scripts', 'req-compile')()
  File "c:\repos\req-compile\req_compile\cmdline.py", line 407, in compile_main
    run_compile(args.requirement_files,
  File "c:\repos\req-compile\req_compile\cmdline.py", line 214, in run_compile
    input_reqs = [_create_input_reqs(input_arg) for input_arg in input_args]
  File "c:\repos\req-compile\req_compile\cmdline.py", line 214, in <listcomp>
    input_reqs = [_create_input_reqs(input_arg) for input_arg in input_args]
  File "c:\repos\req-compile\req_compile\cmdline.py", line 179, in _create_input_reqs
    return DistInfo('-', None, list(itertools.chain(*[_create_stdin_input_req(line)
TypeError: 'DistInfo' object is not iterable

[sputt]

It is attempting to stuff DistInfo metadata about the path into another DistInfo, when they should just be pkg_resources.Requirements. Each directory also has to be added as a --source repo, which it used to do and I broke it