Wait for response

src/regit/__main__.py

@@ -176,18 +176,21 @@ def mktransformer(program, args, batch):
             formatproc = utils.popen(
                 [program] + pargs,
                 stdin=subprocess.PIPE,
+                stdout=subprocess.PIPE,
                 universal_newlines=False,
             )
-            if formatproc.stdin is None:
+            if formatproc.stdin is None or formatproc.stdout is None:
                 raise RuntimeError("Could not start the formatting program")
 
-            fin = formatproc.stdin
+            fin, fout = formatproc.stdin, formatproc.stdout
 
             def transformer(file: Path, content: bytes) -> bytes:
                 with utils.tfile(folder, file.name, content) as tmp_file:
                     try:
+                        with utils.timeit(file.name):
                             fin.write(str(tmp_file).encode("utf-8") + b"\n")  # type: ignore
                             fin.flush()
+                            log.debug("Process respond %s:", fout.readline().encode())
                     except subprocess.CalledProcessError:
                         file = Path(file.name).with_suffix("input").absolute()
                         log.error("Writing argument to %s", file)