From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Couder Subject: [PATCH v2] Documentation: talk about pager in api-trace.txt Date: Mon, 7 Mar 2016 11:38:53 +0100 Message-ID: <1457347133-31733-1-git-send-email-chriscool@tuxfamily.org> Cc: Junio C Hamano , Jeff King , =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= , Karsten Blees , Christian Couder To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Mon Mar 07 11:42:13 2016 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1acsbs-0001vu-Cc for gcvg-git-2@plane.gmane.org; Mon, 07 Mar 2016 11:41:56 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752140AbcCGKlr (ORCPT ); Mon, 7 Mar 2016 05:41:47 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:35301 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbcCGKlp (ORCPT ); Mon, 7 Mar 2016 05:41:45 -0500 Received: by mail-wm0-f42.google.com with SMTP id l68so79425057wml.0 for ; Mon, 07 Mar 2016 02:41:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=Zp9S2YTGGjp1WbAIX9rpwHQgHWn1fX3bQ96DVqz4KHI=; b=QwgMTJlSa6h8WAAskf2TEIQm+k2tjy7isPEDJo01m4wx96yXGmVbifoCPvv7vkNQuu 1ZGpIGYBKPtvUbKoOBFo+ysRCKDdqeA7PwtylSgEwfkdAX5v8xYIIOPGD4sPeSQRTDLN QZWfl2kveiHMhGf2mQNGnE/dutkgswy/BPOwnpYZ5TlklaWp1tGmyujAZRq5/tRP91p+ lZv8ZuohpM7nmE7MSfZMtlRWmagrL6368o/tE2UUGUx8WK/fDpvWR0sZGU0rJemyngf8 7vpAo8plc1Ts+ro62i4YbVlRS7vKfwzAVWjK6t7C9pKoGdV3RWJuImt5eAlVnO4n1fy1 FWyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Zp9S2YTGGjp1WbAIX9rpwHQgHWn1fX3bQ96DVqz4KHI=; b=Df8MCp3NS42qA/CzWT83osx7r4JNAv2XSgwz5qcvXvDPURcaEvGC2AHLzHIZGrH4FT 8tIKv/umkVA0ZRz+5uUfTnx7Mc8d0csVYS5zc23DJAWhN7lPQZyXgeQuKk9etIghhDGP 6w/9GjHENgpRCUEQW2p+WWAUtizcqAmiraVBTD1x6LUi+s/nEw2CQ6fZXiUonQ+ozr7z qdmWFRj+pLQXqihZF9H7rwYFNe0jDqLg6JdV1q0dx4Qj08Wyi8nkiJlkhuD20pDzeS1M 68WLqCL1ckLMo7z361ab9Uw+hCNKxA/vP0dvqutpoZVcztakUXzaYUEMaggx6dHpVoSN G0UA== X-Gm-Message-State: AD7BkJJ+fOlbO/X7yBdVytSoKUma1bUVPhwG0h+SR3vEN2gUewL8RB/3jWLtvo6Py5Cp9w== X-Received: by 10.28.105.136 with SMTP id z8mr12300787wmh.71.1457347304324; Mon, 07 Mar 2016 02:41:44 -0800 (PST) Received: from localhost.localdomain (cha92-h01-128-78-31-246.dsl.sta.abo.bbox.fr. [128.78.31.246]) by smtp.gmail.com with ESMTPSA id h128sm12939191wmf.23.2016.03.07.02.41.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 07 Mar 2016 02:41:43 -0800 (PST) X-Google-Original-From: Christian Couder X-Mailer: git-send-email 2.8.0.rc0.1.gd285ab0 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Signed-off-by: Christian Couder --- Documentation/technical/api-trace.txt | 44 +++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/Documentation/technical/api-trace.txt b/Documentation/technical/api-trace.txt index 097a651..0e1af02 100644 --- a/Documentation/technical/api-trace.txt +++ b/Documentation/technical/api-trace.txt @@ -95,3 +95,47 @@ for (;;) { } trace_performance(t, "frotz"); ------------ + +Bugs & Caveats +-------------- + +GIT_TRACE_* environment variables can be used to tell Git to show +trace output to its standard error stream. Git can often spawn a pager +internally to run its subcommand and send its standard output and +standard error to it. + +Because GIT_TRACE_PERFORMANCE trace is generated only at the very end +of the program with atexit(), which happens after the pager exits, it +would not work well if you send its log to the standard error output +and let Git spawn the pager at the same time. + +As a work around, you can for example use '--no-pager', or set +GIT_TRACE_PERFORMANCE to another file descriptor which is redirected +to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its +absolute path. + +For example instead of the following command which by default may not +print any performance information: + +------------ +GIT_TRACE_PERFORMANCE=2 git log -1 +------------ + +you may want to use: + +------------ +GIT_TRACE_PERFORMANCE=2 git --no-pager log -1 +------------ + +or: + +------------ +GIT_TRACE_PERFORMANCE=3 3>&2 git log -1 +------------ + +or: + +------------ +GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1 +------------ + -- 2.8.0.rc0.1.gd285ab0