fixes #663 and #664. Also fixes owlcat cab

stimela/cargo/base/owlcat/Dockerfile

@@ -1,7 +1,7 @@
-FROM stimela/base:1.6.0
+FROM stimela/base:1.4.6
 RUN docker-apt-install python3-casacore \
     casacore-dev \
     libcfitsio-dev \
     wcslib-dev
-RUN pip install meqtrees-cattery "python-casacore>=3.3.1" "owlcat>=1.6.3" scabha
+RUN pip install meqtrees-cattery "python-casacore>=3.3.1" "owlcat>=1.6.3" scabha future-fstrings
 ENV MEQTREES_CATTERY_PATH /usr/local/lib/python3.6/dist-packages/Cattery

stimela/cargo/cab/wsclean/src/run.py

@@ -59,6 +59,10 @@
 
 _runc = " ".join([cab["binary"]] + args + [mslist])
 
+# This line must never be deleted again. Empires will rise and fall, and certain students will graduate, but this line MUST LIVE ON. When Stimela,
+# Caracal, MeerKAT and SKA are long forgotten ancient history, this line MUST REMAIN. Let it be the last remaining line of Python in history, but let it remain!
+print(_runc) 
+
 try:
     subprocess.check_call(shlex.split(_runc))
 finally:

stimela/utils/xrun_poll.py

@@ -75,32 +75,33 @@ class Poller(object):
     def __init__ (self, log):
         self.fdlabels = {}
         self.log = log
-        self.poll = select.poll()
+        self._poll = select.poll()
 
     def register_file(self, fobj, label):
         self.fdlabels[fobj.fileno()] = label, fobj
-        self.poll.register(fobj.fileno(), select.POLLIN)
+        self._poll.register(fobj.fileno(), select.POLLIN)
 
     def register_process(self, po, label_stdout='stdout', label_stderr='stderr'):
         self.fdlabels[po.stdout.fileno()] = label_stdout, po.stdout
         self.fdlabels[po.stderr.fileno()] = label_stderr, po.stderr
-        self.poll.register(po.stdout.fileno(), select.POLLIN)
-        self.poll.register(po.stderr.fileno(), select.POLLIN)
+        self._poll.register(po.stdout.fileno(), select.POLLIN)
+        self._poll.register(po.stderr.fileno(), select.POLLIN)
 
     def poll(self, timeout=5, verbose=False):
         try:
-            to_read = [fd for (fd, _) in self.poll.poll(timeout)]
+            to_read = self._poll.poll(timeout*1000)
             if verbose:
                 self.log.debug("poll(): ready to read: {}".format(to_read))
-            return [self.fdlabels[fd] for fd in to_read]
+            return [self.fdlabels[fd] for (fd, ev) in to_read]
         except Exception:
             if verbose:
                 self.log.debug("poll() exception: {}".format(traceback.format_exc()))
             raise
 
     def unregister_file(self, fobj):
         if fobj.fileno() in self.fdlabels:
-            self.poll.unregister(fobj.fileno())
+            self._poll.unregister(fobj.fileno())
+            del self.fdlabels[fobj.fileno()]
 
     def __contains__(self, fobj):
         return fobj.fileno() in self.fdlabels
@@ -164,11 +165,13 @@ def xrun(command, options, log=None, logfile=None, env=None, timeout=-1, kill_ca
     try:
         while proc_running and poller.fdlabels:
             fdlist = poller.poll(verbose=DEBUG>0)
+#            print(f"fdlist is {fdlist}")
             for fname, fobj in fdlist:
                 try:
                     line = fobj.readline()
                 except EOFError:
                     line = b''
+#                print("read {} from {}".format(line, fname))
                 empty_line = not line
                 line = (line.decode('utf-8') if type(line) is bytes else line).rstrip()
                 # break out if process closes