blackbox: just try writing to repo.vfs and update lastlogger on success

This is simpler and more robust. Before, an empty ".hg" directory would be
created if it's removed after checking vfs.isdir('.').

hgext/blackbox.py

@@ -1,239 +1,229 b''
 # blackbox.py - log repository events to a file for post-mortem debugging
 #
 # Copyright 2010 Nicolas Dumazet
 # Copyright 2013 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """log repository events to a blackbox for debugging
 
 Logs event information to .hg/blackbox.log to help debug and diagnose problems.
 The events that get logged can be configured via the blackbox.track config key.
 
 Examples::
 
   [blackbox]
   track = *
   # dirty is *EXPENSIVE* (slow);
   # each log entry indicates `+` if the repository is dirty, like :hg:`id`.
   dirty = True
   # record the source of log messages
   logsource = True
 
   [blackbox]
   track = command, commandfinish, commandexception, exthook, pythonhook
 
   [blackbox]
   track = incoming
 
   [blackbox]
   # limit the size of a log file
   maxsize = 1.5 MB
   # rotate up to N log files when the current one gets too big
   maxfiles = 3
 
   [blackbox]
   # Include nanoseconds in log entries with %f (see Python function
   # datetime.datetime.strftime)
   date-format = '%Y-%m-%d @ %H:%M:%S.%f'
 
 """
 
 from __future__ import absolute_import
 
 import errno
 import re
 
 from mercurial.i18n import _
 from mercurial.node import hex
 
 from mercurial import (
     encoding,
     pycompat,
     registrar,
 )
 from mercurial.utils import (
     dateutil,
     procutil,
 )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 cmdtable = {}
 command = registrar.command(cmdtable)
 
 configtable = {}
 configitem = registrar.configitem(configtable)
 
 configitem('blackbox', 'dirty',
     default=False,
 )
 configitem('blackbox', 'maxsize',
     default='1 MB',
 )
 configitem('blackbox', 'logsource',
     default=False,
 )
 configitem('blackbox', 'maxfiles',
     default=7,
 )
 configitem('blackbox', 'track',
     default=lambda: ['*'],
 )
 configitem('blackbox', 'date-format',
     default='%Y/%m/%d %H:%M:%S',
 )
 
 def _openlogfile(ui, vfs):
     def rotate(oldpath, newpath):
         try:
             vfs.unlink(newpath)
         except OSError as err:
             if err.errno != errno.ENOENT:
                 ui.debug("warning: cannot remove '%s': %s\n" %
                          (newpath, err.strerror))
         try:
             if newpath:
                 vfs.rename(oldpath, newpath)
         except OSError as err:
             if err.errno != errno.ENOENT:
                 ui.debug("warning: cannot rename '%s' to '%s': %s\n" %
                          (newpath, oldpath, err.strerror))
 
     maxsize = ui.configbytes('blackbox', 'maxsize')
     name = 'blackbox.log'
     if maxsize > 0:
         try:
             st = vfs.stat(name)
         except OSError:
             pass
         else:
             if st.st_size >= maxsize:
                 path = vfs.join(name)
                 maxfiles = ui.configint('blackbox', 'maxfiles')
                 for i in pycompat.xrange(maxfiles - 1, 1, -1):
                     rotate(oldpath='%s.%d' % (path, i - 1),
                            newpath='%s.%d' % (path, i))
                 rotate(oldpath=path,
                        newpath=maxfiles > 0 and path + '.1')
-    return vfs(name, 'a')
+    return vfs(name, 'a', makeparentdirs=False)
 
 class proxylogger(object):
     """Forward log events to another logger to be set later"""
 
     def __init__(self):
         self.logger = None
 
     def tracked(self, event):
         return self.logger is not None and self.logger.tracked(event)
 
     def log(self, ui, event, msg, opts):
         assert self.logger is not None
         self.logger.log(ui, event, msg, opts)
 
 _lastlogger = proxylogger()
 
 class blackboxlogger(object):
     def __init__(self, ui, repo):
         self._repo = repo
         self._trackedevents = set(ui.configlist('blackbox', 'track'))
 
-    @property
-    def _bbvfs(self):
-        vfs = self._repo.vfs
-        if not vfs.isdir('.'):
-            vfs = None
-        return vfs
-
     def tracked(self, event):
         return b'*' in self._trackedevents or event in self._trackedevents
 
     def log(self, ui, event, msg, opts):
-        if self._bbvfs:
-            _lastlogger.logger = self
-        else:
-            return
-
         default = ui.configdate('devel', 'default-date')
         date = dateutil.datestr(default, ui.config('blackbox', 'date-format'))
         user = procutil.getuser()
         pid = '%d' % procutil.getpid()
         rev = '(unknown)'
         changed = ''
         ctx = self._repo[None]
         parents = ctx.parents()
         rev = ('+'.join([hex(p.node()) for p in parents]))
         if (ui.configbool('blackbox', 'dirty') and
             ctx.dirty(missing=True, merge=False, branch=False)):
             changed = '+'
         if ui.configbool('blackbox', 'logsource'):
             src = ' [%s]' % event
         else:
             src = ''
         try:
             fmt = '%s %s @%s%s (%s)%s> %s'
             args = (date, user, rev, changed, pid, src, msg)
-            with _openlogfile(ui, self._bbvfs) as fp:
+            with _openlogfile(ui, self._repo.vfs) as fp:
                 fp.write(fmt % args)
         except (IOError, OSError) as err:
             # deactivate this to avoid failed logging again
             self._trackedevents.clear()
             ui.debug('warning: cannot write to blackbox.log: %s\n' %
                      encoding.strtolocal(err.strerror))
+            return
+        _lastlogger.logger = self
 
 def uipopulate(ui):
     ui.setlogger(b'blackbox', _lastlogger)
 
 def reposetup(ui, repo):
     # During 'hg pull' a httppeer repo is created to represent the remote repo.
     # It doesn't have a .hg directory to put a blackbox in, so we don't do
     # the blackbox setup for it.
     if not repo.local():
         return
 
     # Since blackbox.log is stored in the repo directory, the logger should be
     # instantiated per repository.
     logger = blackboxlogger(ui, repo)
     ui.setlogger(b'blackbox', logger)
 
     # Set _lastlogger even if ui.log is not called. This gives blackbox a
     # fallback place to log
     if _lastlogger.logger is None:
         _lastlogger.logger = logger
 
     repo._wlockfreeprefix.add('blackbox.log')
 
 @command('blackbox',
     [('l', 'limit', 10, _('the number of events to show')),
     ],
     _('hg blackbox [OPTION]...'),
     helpcategory=command.CATEGORY_MAINTENANCE,
     helpbasic=True)
 def blackbox(ui, repo, *revs, **opts):
     '''view the recent repository events
     '''
 
     if not repo.vfs.exists('blackbox.log'):
         return
 
     limit = opts.get(r'limit')
     fp = repo.vfs('blackbox.log', 'r')
     lines = fp.read().split('\n')
 
     count = 0
     output = []
     for line in reversed(lines):
         if count >= limit:
             break
 
         # count the commands by matching lines like: 2013/01/23 19:13:36 root>
         if re.match('^\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} .*> .*', line):
             count += 1
         output.append(line)
 
     ui.status('\n'.join(reversed(output)))

tests/test-blackbox.t

@@ -1,428 +1,451 b''
 setup
 
   $ cat > myextension.py <<EOF
   > from mercurial import error, registrar
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > @command(b'crash', [], b'hg crash')
   > def crash(ui, *args, **kwargs):
   >     raise Exception("oops")
   > @command(b'abort', [], b'hg abort')
   > def abort(ui, *args, **kwargs):
   >     raise error.Abort(b"oops")
   > EOF
   $ abspath=`pwd`/myextension.py
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > blackbox=
   > mock=$TESTDIR/mockblackbox.py
   > mq=
   > myextension=$TESTTMP/myextension.py
   > [alias]
   > confuse = log --limit 3
   > so-confusing = confuse --style compact
   > EOF
 
   $ hg init blackboxtest
   $ cd blackboxtest
 
 command, exit codes, and duration
 
   $ echo a > a
   $ hg add a
   $ hg blackbox --config blackbox.dirty=True
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> init blackboxtest exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> add a
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> add a exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000+ (5000)> blackbox --config *blackbox.dirty=True* (glob)
 
 failure exit code
   $ rm ./.hg/blackbox.log
   $ hg add non-existent
   non-existent: $ENOENT$
   [1]
   $ hg blackbox
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> add non-existent
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> add non-existent exited 1 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox
 
 abort exit code
   $ rm ./.hg/blackbox.log
   $ hg abort 2> /dev/null
   [255]
   $ hg blackbox -l 2
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> abort exited 255 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox -l 2
 
 unhandled exception
   $ rm ./.hg/blackbox.log
   $ hg crash 2> /dev/null
   [1]
   $ hg blackbox -l 2
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> crash exited 1 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox -l 2
 
 alias expansion is logged
   $ rm ./.hg/blackbox.log
   $ hg confuse
   $ hg blackbox
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> confuse
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> alias 'confuse' expands to 'log --limit 3'
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> confuse exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox
 
 recursive aliases work correctly
   $ rm ./.hg/blackbox.log
   $ hg so-confusing
   $ hg blackbox
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> so-confusing
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> alias 'so-confusing' expands to 'confuse --style compact'
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> alias 'confuse' expands to 'log --limit 3'
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> so-confusing exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox
 
 custom date format
   $ rm ./.hg/blackbox.log
   $ hg --config blackbox.date-format='%Y-%m-%d @ %H:%M:%S' \
   >    --config devel.default-date='1334347993 0' --traceback status
   A a
   $ hg blackbox
   2012-04-13 @ 20:13:13 bob @0000000000000000000000000000000000000000 (5000)> --config *blackbox.date-format=%Y-%m-%d @ %H:%M:%S* --config *devel.default-date=1334347993 0* --traceback status (glob)
   2012-04-13 @ 20:13:13 bob @0000000000000000000000000000000000000000 (5000)> --config *blackbox.date-format=%Y-%m-%d @ %H:%M:%S* --config *devel.default-date=1334347993 0* --traceback status exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox
 
 incoming change tracking
 
 create two heads to verify that we only see one change in the log later
   $ hg commit -ma
   $ hg up null
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo b > b
   $ hg commit -Amb
   adding b
   created new head
 
 clone, commit, pull
   $ hg clone . ../blackboxtest2
   updating to branch default
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo c > c
   $ hg commit -Amc
   adding c
   $ cd ../blackboxtest2
   $ hg pull
   pulling from $TESTTMP/blackboxtest
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files
   new changesets d02f48003e62
   (run 'hg update' to get a working copy)
   $ hg blackbox -l 6
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> pull
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> updated served branch cache in * seconds (glob)
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> wrote served branch cache with 1 labels and 2 nodes
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> 1 incoming changes - new heads: d02f48003e62
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> pull exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> blackbox -l 6
 
 we must not cause a failure if we cannot write to the log
 
   $ hg rollback
   repository tip rolled back to revision 1 (undo pull)
 
   $ mv .hg/blackbox.log .hg/blackbox.log-
   $ mkdir .hg/blackbox.log
   $ hg --debug incoming
   warning: cannot write to blackbox.log: * (glob)
   comparing with $TESTTMP/blackboxtest
   query 1; heads
   searching for changes
   all local heads known remotely
   changeset:   2:d02f48003e62c24e2659d97d30f2a83abe5d5d51
   tag:         tip
   phase:       draft
   parent:      1:6563da9dcf87b1949716e38ff3e3dfaa3198eb06
   parent:      -1:0000000000000000000000000000000000000000
   manifest:    2:ab9d46b053ebf45b7996f2922b9893ff4b63d892
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   files+:      c
   extra:       branch=default
   description:
   c
   
   
   $ hg pull
   pulling from $TESTTMP/blackboxtest
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files
   new changesets d02f48003e62
   (run 'hg update' to get a working copy)
 
 a failure reading from the log is fatal
 
   $ hg blackbox -l 3
   abort: *$TESTTMP/blackboxtest2/.hg/blackbox.log* (glob)
   [255]
 
   $ rmdir .hg/blackbox.log
   $ mv .hg/blackbox.log- .hg/blackbox.log
 
 backup bundles get logged
 
   $ touch d
   $ hg commit -Amd
   adding d
   created new head
   $ hg strip tip
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob)
   $ hg blackbox -l 6
   1970/01/01 00:00:00 bob @73f6ee326b27d820b0472f1a825e3a50f3dc489b (5000)> strip tip
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/73f6ee326b27-7612e004-backup.hg
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> updated base branch cache in * seconds (glob)
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> wrote base branch cache with 1 labels and 2 nodes
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> strip tip exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> blackbox -l 6
 
 extension and python hooks - use the eol extension for a pythonhook
 
   $ echo '[extensions]' >> .hg/hgrc
   $ echo 'eol=' >> .hg/hgrc
   $ echo '[hooks]' >> .hg/hgrc
   $ echo 'update = echo hooked' >> .hg/hgrc
   $ hg update
   The fsmonitor extension is incompatible with the eol extension and has been disabled. (fsmonitor !)
   hooked
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   updated to "d02f48003e62: c"
   1 other heads for branch "default"
   $ cat >> .hg/hgrc <<EOF
   > [extensions]
   > # disable eol, because it is not needed for subsequent tests
   > # (in addition, keeping it requires extra care for fsmonitor)
   > eol=!
   > EOF
   $ hg blackbox -l 5
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> update (no-chg !)
   1970/01/01 00:00:00 bob @6563da9dcf87b1949716e38ff3e3dfaa3198eb06 (5000)> pythonhook-preupdate: hgext.eol.preupdate finished in * seconds (glob)
   1970/01/01 00:00:00 bob @d02f48003e62c24e2659d97d30f2a83abe5d5d51 (5000)> exthook-update: echo hooked finished in * seconds (glob)
   1970/01/01 00:00:00 bob @d02f48003e62c24e2659d97d30f2a83abe5d5d51 (5000)> update exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @d02f48003e62c24e2659d97d30f2a83abe5d5d51 (5000)> serve --cmdserver chgunix --address $TESTTMP.chgsock/server.* --daemon-postexec 'chdir:/' (glob) (chg !)
   1970/01/01 00:00:00 bob @d02f48003e62c24e2659d97d30f2a83abe5d5d51 (5000)> blackbox -l 5
 
 log rotation
 
   $ echo '[blackbox]' >> .hg/hgrc
   $ echo 'maxsize = 20 b' >> .hg/hgrc
   $ echo 'maxfiles = 3' >> .hg/hgrc
   $ hg status
   $ hg status
   $ hg status
   $ hg tip -q
   2:d02f48003e62
   $ ls .hg/blackbox.log*
   .hg/blackbox.log
   .hg/blackbox.log.1
   .hg/blackbox.log.2
   $ cd ..
 
   $ hg init blackboxtest3
   $ cd blackboxtest3
   $ hg blackbox
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> init blackboxtest3 exited 0 after * seconds (glob)
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> blackbox
   $ mv .hg/blackbox.log .hg/blackbox.log-
   $ mkdir .hg/blackbox.log
   $ sed -e 's/\(.*test1.*\)/#\1/; s#\(.*commit2.*\)#os.rmdir(".hg/blackbox.log")\
   > os.rename(".hg/blackbox.log-", ".hg/blackbox.log")\
   > \1#' $TESTDIR/test-dispatch.py > ../test-dispatch.py
   $ "$PYTHON" $TESTDIR/blackbox-readonly-dispatch.py
   running: --debug add foo
   warning: cannot write to blackbox.log: Is a directory (no-windows !)
   warning: cannot write to blackbox.log: $TESTTMP/blackboxtest3/.hg/blackbox.log: Access is denied (windows !)
   adding foo
   result: 0
   running: --debug commit -m commit1 -d 2000-01-01 foo
   warning: cannot write to blackbox.log: Is a directory (no-windows !)
   warning: cannot write to blackbox.log: $TESTTMP/blackboxtest3/.hg/blackbox.log: Access is denied (windows !)
   committing files:
   foo
   committing manifest
   committing changelog
   updating the branch cache
   committed changeset 0:0e46349438790c460c5c9f7546bfcd39b267bbd2
   result: 0
   running: --debug commit -m commit2 -d 2000-01-02 foo
   committing files:
   foo
   committing manifest
   committing changelog
   updating the branch cache
   committed changeset 1:45589e459b2edfbf3dbde7e01f611d2c1e7453d7
   result: 0
   running: --debug log -r 0
   changeset:   0:0e46349438790c460c5c9f7546bfcd39b267bbd2
   phase:       draft
   parent:      -1:0000000000000000000000000000000000000000
   parent:      -1:0000000000000000000000000000000000000000
   manifest:    0:9091aa5df980aea60860a2e39c95182e68d1ddec
   user:        test
   date:        Sat Jan 01 00:00:00 2000 +0000
   files+:      foo
   extra:       branch=default
   description:
   commit1
   
   
   result: 0
   running: --debug log -r tip
   changeset:   1:45589e459b2edfbf3dbde7e01f611d2c1e7453d7
   tag:         tip
   phase:       draft
   parent:      0:0e46349438790c460c5c9f7546bfcd39b267bbd2
   parent:      -1:0000000000000000000000000000000000000000
   manifest:    1:895aa9b7886f89dd017a6d62524e1f9180b04df9
   user:        test
   date:        Sun Jan 02 00:00:00 2000 +0000
   files:       foo
   extra:       branch=default
   description:
   commit2
   
   
   result: 0
   $ hg blackbox
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> updating the branch cache
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> updated served branch cache in * seconds (glob)
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> wrote served branch cache with 1 labels and 1 nodes
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> --debug commit -m commit2 -d 2000-01-02 foo exited 0 after *.?? seconds (glob)
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> --debug log -r 0
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> writing .hg/cache/tags2-visible with 0 tags
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> --debug log -r 0 exited 0 after *.?? seconds (glob)
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> --debug log -r tip
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> --debug log -r tip exited 0 after *.?? seconds (glob)
   1970/01/01 00:00:00 bob @45589e459b2edfbf3dbde7e01f611d2c1e7453d7 (5000)> blackbox
 
 Test log recursion from dirty status check
 
   $ cat > ../r.py <<EOF
   > from mercurial import context, error, extensions
   > x=[False]
   > def status(orig, *args, **opts):
   >     args[0].repo().ui.log(b"broken", b"recursion?")
   >     return orig(*args, **opts)
   > def reposetup(ui, repo):
   >     extensions.wrapfunction(context.basectx, 'status', status)
   > EOF
   $ hg id --config extensions.x=../r.py --config blackbox.dirty=True
   45589e459b2e tip
 
 cleanup
   $ cd ..
 
+Test missing log directory, which shouldn't be created automatically
+
+  $ cat <<'EOF' > closeremove.py
+  > def reposetup(ui, repo):
+  >     class rmrepo(repo.__class__):
+  >         def close(self):
+  >             super(rmrepo, self).close()
+  >             self.ui.debug(b'removing %s\n' % self.vfs.base)
+  >             self.vfs.rmtree()
+  >     repo.__class__ = rmrepo
+  > EOF
+
+  $ hg init gone
+  $ cd gone
+  $ cat <<'EOF' > .hg/hgrc
+  > [extensions]
+  > closeremove = ../closeremove.py
+  > EOF
+  $ hg log --debug
+  removing $TESTTMP/gone/.hg
+  warning: cannot write to blackbox.log: $ENOENT$
+  $ cd ..
+
 #if chg
 
 when using chg, blackbox.log should get rotated correctly
 
   $ cat > $TESTTMP/noop.py << EOF
   > from __future__ import absolute_import
   > import time
   > from mercurial import registrar, scmutil
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > @command('noop')
   > def noop(ui, repo):
   >     pass
   > EOF
 
   $ hg init blackbox-chg
   $ cd blackbox-chg
 
   $ cat > .hg/hgrc << EOF
   > [blackbox]
   > maxsize = 500B
   > [extensions]
   > # extension change forces chg to restart
   > noop=$TESTTMP/noop.py
   > EOF
 
   $ "$PYTHON" -c 'print("a" * 400)' > .hg/blackbox.log
   $ chg noop
   $ chg noop
   $ chg noop
   $ chg noop
   $ chg noop
 
   $ cat > showsize.py << 'EOF'
   > import os
   > import sys
   > limit = 500
   > for p in sys.argv[1:]:
   >     size = os.stat(p).st_size
   >     if size >= limit:
   >         desc = '>='
   >     else:
   >         desc = '<'
   >     print('%s: %s %d' % (p, desc, limit))
   > EOF
 
   $ "$PYTHON" showsize.py .hg/blackbox*
   .hg/blackbox.log: < 500
   .hg/blackbox.log.1: >= 500
   .hg/blackbox.log.2: >= 500
 
   $ cd ..
 
 With chg, blackbox should not create the log file if the repo is gone
 
   $ hg init repo1
   $ hg --config extensions.a=! -R repo1 log
   $ rm -rf $TESTTMP/repo1
   $ hg --config extensions.a=! init repo1
 
 #endif
 
 blackbox should work if repo.ui.log is not called (issue5518)
 
   $ cat > $TESTTMP/raise.py << EOF
   > from __future__ import absolute_import
   > from mercurial import registrar, scmutil
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > @command(b'raise')
   > def raisecmd(*args):
   >     raise RuntimeError('raise')
   > EOF
 
   $ cat >> $HGRCPATH << EOF
   > [blackbox]
   > track = commandexception
   > [extensions]
   > raise=$TESTTMP/raise.py
   > EOF
 
   $ hg init $TESTTMP/blackbox-exception-only
   $ cd $TESTTMP/blackbox-exception-only
 
 #if chg
  (chg exits 255 because it fails to receive an exit code)
   $ hg raise 2>/dev/null
   [255]
 #else
  (hg exits 1 because Python default exit code for uncaught exception is 1)
   $ hg raise 2>/dev/null
   [1]
 #endif
 
   $ head -1 .hg/blackbox.log
   1970/01/01 00:00:00 bob @0000000000000000000000000000000000000000 (5000)> ** Unknown exception encountered with possibly-broken third-party extension mock
   $ tail -2 .hg/blackbox.log
   RuntimeError: raise