Refactor logging of uninst

Signed-off-by: Niels Thykier <niels@thykier.net>

britney.py

@@ -204,7 +204,7 @@ from britney2.policies.autopkgtest import AutopkgtestPolicy
 from britney2.utils import (old_libraries_format, undo_changes,
                             compute_reverse_tree, possibly_compressed,
                             read_nuninst, write_nuninst, write_heidi,
-                            eval_uninst, newly_uninst, make_migrationitem,
+                            format_and_log_uninst, newly_uninst, make_migrationitem,
                             write_excuses, write_heidi_delta, write_controlfiles,
                             old_libraries, is_nuninst_asgood_generous,
                             clone_nuninst, check_installability,
@@ -2283,8 +2283,10 @@ class Britney(object):
         self.output_write(" finish: [%s]\n" % ",".join( x.uvname for x in selected ))
         self.output_write("endloop: %s\n" % (self.eval_nuninst(self.nuninst_orig)))
         self.output_write("    now: %s\n" % (self.eval_nuninst(nuninst_last_accepted)))
-        self.output_write(eval_uninst(self.options.architectures,
-                                      newly_uninst(self.nuninst_orig, nuninst_last_accepted)))
+        format_and_log_uninst(self.output_logger,
+                              self.options.architectures,
+                              newly_uninst(self.nuninst_orig, nuninst_last_accepted)
+                              )
         self.output_write("\n")
 
         return (nuninst_last_accepted, maybe_rescheduled_packages)
@@ -2355,8 +2357,10 @@ class Britney(object):
             self.output_write("easy: %s\n" % nuninst_end_str)
 
             if not force:
-                self.output_write(eval_uninst(self.options.architectures,
-                                              newly_uninst(nuninst_start, nuninst_end)))
+                format_and_log_uninst(self.output_logger,
+                                      self.options.architectures,
+                                      newly_uninst(nuninst_start, nuninst_end)
+                                      )
 
         if force:
             # Force implies "unconditionally better"
@@ -2381,9 +2385,16 @@ class Britney(object):
             self.output_write(" orig: %s\n" % self.eval_nuninst(self.nuninst_orig))
             self.output_write("  end: %s\n" % nuninst_end_str)
             if force:
-                self.output_write("force breaks:\n")
-                self.output_write(eval_uninst(self.options.architectures,
-                                              newly_uninst(nuninst_start, nuninst_end)))
+                broken = newly_uninst(nuninst_start, nuninst_end)
+                if broken:
+                    self.output_logger.warning("force breaks:")
+                    format_and_log_uninst(self.output_logger,
+                                          self.options.architectures,
+                                          broken,
+                                          loglevel=logging.WARNING,
+                                          )
+                else:
+                    self.output_logger.info("force did not break any packages")
             self.output_write("SUCCESS (%d/%d)\n" % (len(actions or self.upgrade_me), len(extra)))
             self.nuninst_orig = nuninst_end
             self.all_selected += selected
@@ -2562,12 +2573,16 @@ class Britney(object):
 
     def printuninstchange(self):
         self.logger.info("Checking for newly uninstallable packages")
-        text = eval_uninst(self.options.architectures, newly_uninst(
-                        self.nuninst_orig_save, self.nuninst_orig))
+        uninst = newly_uninst(self.nuninst_orig_save, self.nuninst_orig)
 
-        if text != '':
-            self.output_write("\nNewly uninstallable packages in testing:\n%s" % \
-                (text))
+        if uninst:
+            self.output_logger.warning("")
+            self.output_logger.warning("Newly uninstallable packages in testing:")
+            format_and_log_uninst(self.output_logger,
+                                  self.options.architectures,
+                                  uninst,
+                                  loglevel=logging.WARNING,
+                                  )
 
     def hint_tester(self):
         """Run a command line interface to test hints

britney2/utils.py

@@ -23,6 +23,7 @@
 
 import apt_pkg
 import errno
+import logging
 import os
 import sys
 import time
@@ -234,28 +235,32 @@ def newly_uninst(nuold, nunew):
     "nunew" from the statistic "nuold".
 
     It returns a dictionary with the architectures as keys and the list
-    of uninstallable packages as values.
+    of uninstallable packages as values.  If there are no regressions
+    on a given architecture, then the architecture will be omitted in
+    the result.  Accordingly, if none of the architectures have
+    regressions an empty directory is returned.
     """
     res = {}
     for arch in ifilter_only(nunew, nuold):
-        res[arch] = [x for x in nunew[arch] if x not in nuold[arch]]
+        arch_nuninst = [x for x in nunew[arch] if x not in nuold[arch]]
+        # Leave res empty if there are no newly uninst packages
+        if arch_nuninst:
+            res[arch] = arch_nuninst
     return res
 
 
-def eval_uninst(architectures, nuninst):
-    """Return a string which represents the uninstallable packages
-
-    This method returns a string which represents the uninstallable
-    packages reading the uninstallability statistics "nuninst".
+def format_and_log_uninst(logger, architectures, nuninst, *, loglevel=logging.INFO):
+    """Emits the uninstallable packages to the log
 
     An example of the output string is:
       * i386: broken-pkg1, broken-pkg2
+
+    Note that if there is no uninstallable packages, then nothing is emitted.
     """
-    parts = []
     for arch in architectures:
         if arch in nuninst and nuninst[arch]:
-            parts.append("    * %s: %s\n" % (arch,", ".join(sorted(nuninst[arch]))))
-    return "".join(parts)
+            msg = "    * %s: %s" % (arch, ", ".join(sorted(nuninst[arch])))
+            logger.log(loglevel, msg)
 
 
 def write_heidi(filename, sources_t, packages_t, *, outofsync_arches=frozenset(), sorted=sorted):