benchmarks: restore `output` variable lost in D10884

Noticed by pyflakes (which I didn't have installed for Python 3.9 when
I sent D10884).

Differential Revision: https://phab.mercurial-scm.org/D10894

contrib/benchmarks/__init__.py

@@ -1,125 +1,126 b''
 # __init__.py - asv benchmark suite
 #
 # Copyright 2016 Logilab SA <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 # "historical portability" policy of contrib/benchmarks:
 #
 # We have to make this code work correctly with current mercurial stable branch
 # and if possible with reasonable cost with early Mercurial versions.
 
 '''ASV (https://asv.readthedocs.io) benchmark suite
 
 Benchmark are parameterized against reference repositories found in the
 directory pointed by the REPOS_DIR environment variable.
 
 Invocation example:
 
     $ export REPOS_DIR=~/hgperf/repos
     # run suite on given revision
     $ asv --config contrib/asv.conf.json run REV
     # run suite on new changesets found in stable and default branch
     $ asv --config contrib/asv.conf.json run NEW
     # display a comparative result table of benchmark results between two given
     # revisions
     $ asv --config contrib/asv.conf.json compare REV1 REV2
     # compute regression detection and generate ASV static website
     $ asv --config contrib/asv.conf.json publish
     # serve the static website
     $ asv --config contrib/asv.conf.json preview
 '''
 
 from __future__ import absolute_import
 
 import functools
 import os
 import re
 
 from mercurial import (
     extensions,
     hg,
     ui as uimod,
     util,
 )
 
 basedir = os.path.abspath(
     os.path.join(os.path.dirname(__file__), os.path.pardir, os.path.pardir)
 )
 reposdir = os.environ['REPOS_DIR']
 reposnames = [
     name
     for name in os.listdir(reposdir)
     if os.path.isdir(os.path.join(reposdir, name, ".hg"))
 ]
 if not reposnames:
     raise ValueError("No repositories found in $REPO_DIR")
 outputre = re.compile(
     (
         r'! wall (\d+.\d+) comb \d+.\d+ user \d+.\d+ sys '
         r'\d+.\d+ \(best of \d+\)'
     )
 )
 
 
 def runperfcommand(reponame, command, *args, **kwargs):
     os.environ["HGRCPATH"] = os.environ.get("ASVHGRCPATH", "")
     # for "historical portability"
     # ui.load() has been available since d83ca85
     if util.safehasattr(uimod.ui, "load"):
         ui = uimod.ui.load()
     else:
         ui = uimod.ui()
     repo = hg.repository(ui, os.path.join(reposdir, reponame))
     perfext = extensions.load(
         ui, 'perfext', os.path.join(basedir, 'contrib', 'perf.py')
     )
     cmd = getattr(perfext, command)
-    with ui.silent():
+    ui.pushbuffer()
         cmd(ui, repo, *args, **kwargs)
+    output = ui.popbuffer()
     match = outputre.search(output)
     if not match:
         raise ValueError("Invalid output {}".format(output))
     return float(match.group(1))
 
 
 def perfbench(repos=reposnames, name=None, params=None):
     """decorator to declare ASV benchmark based on contrib/perf.py extension
 
     An ASV benchmark is a python function with the given attributes:
 
     __name__: should start with track_, time_ or mem_ to be collected by ASV
     params and param_name: parameter matrix to display multiple graphs on the
     same page.
     pretty_name: If defined it's displayed in web-ui instead of __name__
     (useful for revsets)
     the module name is prepended to the benchmark name and displayed as
     "category" in webui.
 
     Benchmarks are automatically parameterized with repositories found in the
     REPOS_DIR environment variable.
 
     `params` is the param matrix in the form of a list of tuple
     (param_name, [value0, value1])
 
     For example [(x, [a, b]), (y, [c, d])] declare benchmarks for
     (a, c), (a, d), (b, c) and (b, d).
     """
     params = list(params or [])
     params.insert(0, ("repo", repos))
 
     def decorator(func):
         @functools.wraps(func)
         def wrapped(repo, *args):
             def perf(command, *a, **kw):
                 return runperfcommand(repo, command, *a, **kw)
 
             return func(perf, *args)
 
         wrapped.params = [p[1] for p in params]
         wrapped.param_names = [p[0] for p in params]
         wrapped.pretty_name = name
         return wrapped
 
     return decorator