Merge branch 'sg/trace2-rename'

Rename environment variables that are used to control the "trace2"
mechanism to a more readable name.

* sg/trace2-rename:
  trace2: document the supported values of GIT_TRACE2* env variables
  trace2: rename environment variables to GIT_TRACE2*

13 files changed, 118 insertions, 91 deletions

diff --git a/Documentation/config/trace2.txt b/Documentation/config/trace2.txt
index a5f409c1c1..2edbfb02fe 100644
--- a/Documentation/config/trace2.txt
+++ b/Documentation/config/trace2.txt
@@ -4,17 +4,17 @@ command line arguments are not respected.
 
 trace2.normalTarget::
 	This variable controls the normal target destination.
-	It may be overridden by the `GIT_TR2` environment variable.
+	It may be overridden by the `GIT_TRACE2` environment variable.
 	The following table shows possible values.
 
 trace2.perfTarget::
 	This variable controls the performance target destination.
-	It may be overridden by the `GIT_TR2_PERF` environment variable.
+	It may be overridden by the `GIT_TRACE2_PERF` environment variable.
 	The following table shows possible values.
 
 trace2.eventTarget::
 	This variable controls the event target destination.
-	It may be overridden by the `GIT_TR2_EVENT` environment variable.
+	It may be overridden by the `GIT_TRACE2_EVENT` environment variable.
 	The following table shows possible values.
 +
 include::../trace2-target-values.txt[]
@@ -22,22 +22,22 @@ include::../trace2-target-values.txt[]
 trace2.normalBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from normal output.  May be overridden by the
-	`GIT_TR2_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_BRIEF` environment variable.  Defaults to false.
 
 trace2.perfBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from PERF output.  May be overridden by the
-	`GIT_TR2_PERF_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_PERF_BRIEF` environment variable.  Defaults to false.
 
 trace2.eventBrief::
 	Boolean.  When true `time`, `filename`, and `line` fields are
 	omitted from event output.  May be overridden by the
-	`GIT_TR2_EVENT_BRIEF` environment variable.  Defaults to false.
+	`GIT_TRACE2_EVENT_BRIEF` environment variable.  Defaults to false.
 
 trace2.eventNesting::
 	Integer.  Specifies desired depth of nested regions in the
 	event output.  Regions deeper than this value will be
-	omitted.  May be overridden by the `GIT_TR2_EVENT_NESTING`
+	omitted.  May be overridden by the `GIT_TRACE2_EVENT_NESTING`
 	environment variable.  Defaults to 2.
 
 trace2.configParams::
@@ -45,7 +45,7 @@ trace2.configParams::
 	settings that should be recorded in the trace2 output.
 	For example, `core.*,remote.*.url` would cause the trace2
 	output to contain events listing each configured remote.
-	May be overridden by the `GIT_TR2_CONFIG_PARAMS` environment
+	May be overridden by the `GIT_TRACE2_CONFIG_PARAMS` environment
 	variable.  Unset by default.
 
 trace2.destinationDebug::
@@ -53,4 +53,4 @@ trace2.destinationDebug::
 	trace target destination cannot be opened for writing.
 	By default, these errors are suppressed and tracing is
 	silently disabled.  May be overridden by the
-	`GIT_TR2_DST_DEBUG` environment variable.
+	`GIT_TRACE2_DST_DEBUG` environment variable.
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 72adfcc5e2..6ddc1e2ca6 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -660,26 +660,53 @@ of clones and fetches.
 	When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
 	data (that is, only dump info lines and headers).
 
-`GIT_TR2`::
+`GIT_TRACE2`::
 	Enables more detailed trace messages from the "trace2" library.
-	Output from `GIT_TR2` is a simple text-based format for human
+	Output from `GIT_TRACE2` is a simple text-based format for human
 	readability.
 +
-The `GIT_TR2` variables can take many values. Any value available to
-the `GIT_TRACE` variables is also available to `GIT_TR2`. The `GIT_TR2`
-variables can also specify a Unix Domain Socket. See
-link:technical/api-trace2.html[Trace2 documentation] for full details.
+If this variable is set to "1", "2" or "true" (comparison
+is case insensitive), trace messages will be printed to
+stderr.
++
+If the variable is set to an integer value greater than 2
+and lower than 10 (strictly) then Git will interpret this
+value as an open file descriptor and will try to write the
+trace messages into this file descriptor.
++
+Alternatively, if the variable is set to an absolute path
+(starting with a '/' character), Git will interpret this
+as a file path and will try to append the trace messages
+to it.  If the path already exists and is a directory, the
+trace messages will be written to files (one per process)
+in that directory, named according to the last component
+of the SID and an optional counter (to avoid filename
+collisions).
++
+In addition, if the variable is set to
+`af_unix:[<socket_type>:]<absolute-pathname>`, Git will try
+to open the path as a Unix Domain Socket.  The socket type
+can be either `stream` or `dgram`.
++
+Unsetting the variable, or setting it to empty, "0" or
+"false" (case insensitive) disables trace messages.
++
+See link:technical/api-trace2.html[Trace2 documentation]
+for full details.
+
 
-`GIT_TR2_EVENT`::
+`GIT_TRACE2_EVENT`::
 	This setting writes a JSON-based format that is suited for machine
-	interpretation. See link:technical/api-trace2.html[Trace2 documentation]
-	for full details.
+	interpretation.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
 
-`GIT_TR2_PERF`::
-	In addition to the text-based messages available in `GIT_TR2`, this
+`GIT_TRACE2_PERF`::
+	In addition to the text-based messages available in `GIT_TRACE2`, this
 	setting writes a column-based format for understanding nesting
-	regions. See link:technical/api-trace2.html[Trace2 documentation]
-	for full details.
+	regions.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
 
 `GIT_REDACT_COOKIES`::
 	This can be set to a comma-separated list of strings. When a curl trace
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index 9e585b8e79..23c3cc7a37 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -23,7 +23,7 @@ formats in the future.  This might be used to define a binary format,
 for example.
 
 Trace2 is controlled using `trace2.*` config values in the system and
-global config files and `GIT_TR2*` environment variables.  Trace2 does
+global config files and `GIT_TRACE2*` environment variables.  Trace2 does
 not read from repo local or worktree config files or respect `-c`
 command line config settings.
 
@@ -42,7 +42,7 @@ config setting.
 For example
 
 ------------
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2=~/log.normal
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -71,13 +71,13 @@ $ cat ~/log.normal
 The performance format target (PERF) is a column-based format to
 replace GIT_TRACE_PERFORMANCE and is suitable for development and
 testing, possibly to complement tools like gprof.  This format is
-enabled with the `GIT_TR2_PERF` environment variable or the
+enabled with the `GIT_TRACE2_PERF` environment variable or the
 `trace2.perfTarget` system or global config setting.
 
 For example
 
 ------------
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -104,14 +104,14 @@ $ cat ~/log.perf
 === The Event Format Target
 
 The event format target is a JSON-based format of event data suitable
-for telemetry analysis.  This format is enabled with the `GIT_TR2_EVENT`
+for telemetry analysis.  This format is enabled with the `GIT_TRACE2_EVENT`
 environment variable or the `trace2.eventTarget` system or global config
 setting.
 
 For example
 
 ------------
-$ export GIT_TR2_EVENT=~/log.event
+$ export GIT_TRACE2_EVENT=~/log.event
 $ git version
 git version 2.20.1.155.g426c96fcdb
 ------------
@@ -273,7 +273,7 @@ significantly affects program performance or behavior, such as
 	Emits a "def_param" messages for "important" configuration
 	settings.
 +
-The environment variable `GIT_TR2_CONFIG_PARAMS` or the `trace2.configParams`
+The environment variable `GIT_TRACE2_CONFIG_PARAMS` or the `trace2.configParams`
 config value can be set to a
 list of patterns of important configuration settings, for example:
 `core.*,remote.*.url`.  This function will iterate over all config
@@ -465,7 +465,7 @@ Events are written as lines of the form:
 Note that this may contain embedded LF or CRLF characters that are
 not escaped, so the event may spill across multiple lines.
 
-If `GIT_TR2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+If `GIT_TRACE2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
 and `line` fields are omitted.
 
 This target is intended to be more of a summary (like GIT_TRACE) and
@@ -533,7 +533,7 @@ This field is in anticipation of in-proc submodules in the future.
 15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
 ------------
 
-If `GIT_TR2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+If `GIT_TRACE2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
 and `line` fields are omitted.
 
 ------------
@@ -598,7 +598,7 @@ The following key/value pairs are common to all events:
 `"repo":<repo-id>`::
 	when present, is the integer repo-id as described previously.
 
-If `GIT_TR2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+If `GIT_TRACE2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
 and `line` fields are omitted from all events and the `time` field is
 only present on the "start" and "atexit" events.
 
@@ -911,7 +911,7 @@ visited.
 The `category` field may be used in a future enhancement to
 do category-based filtering.
 +
-`GIT_TR2_EVENT_NESTING` or `trace2.eventNesting` can be used to
+`GIT_TRACE2_EVENT_NESTING` or `trace2.eventNesting` can be used to
 filter deeply nested regions and data events.  It defaults to "2".
 
 `"region_leave"`::
@@ -1039,8 +1039,8 @@ rev-list, and gc.  This example also shows that fetch took
 5.199 seconds and of that 4.932 was in ssh.
 +
 ----------------
-$ export GIT_TR2_BRIEF=1
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
 $ git fetch origin
 ...
 ----------------
@@ -1075,8 +1075,8 @@ its name as "gc", it also reports the hierarchy as "fetch/gc".
 indented for clarity.)
 +
 ----------------
-$ export GIT_TR2_BRIEF=1
-$ export GIT_TR2=~/log.normal
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
 $ git fetch origin
 ...
 ----------------
@@ -1134,8 +1134,8 @@ In this example, scanning for untracked files ran from +0.012568 to
 +0.027149 (since the process started) and took 0.014581 seconds.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 
@@ -1180,8 +1180,8 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 We can further investigate the time spent scanning for untracked files.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf
@@ -1236,8 +1236,8 @@ int read_index_from(struct index_state *istate, const char *path,
 This example shows that the index contained 3552 entries.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf
@@ -1310,8 +1310,8 @@ Data events are tagged with the active thread name.  They are used
 to report the per-thread parameters.
 +
 ----------------
-$ export GIT_TR2_PERF_BRIEF=1
-$ export GIT_TR2_PERF=~/log.perf
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
 $ git status
 ...
 $ cat ~/log.perf
diff --git a/t/t0001-init.sh b/t/t0001-init.sh
index 1f462204ea..77a224aafb 100755
--- a/t/t0001-init.sh
+++ b/t/t0001-init.sh
@@ -93,7 +93,7 @@ test_expect_success 'No extra GIT_* on alias scripts' '
 		sed -n \
 			-e "/^GIT_PREFIX=/d" \
 			-e "/^GIT_TEXTDOMAINDIR=/d" \
-			-e "/^GIT_TR2_PARENT/d" \
+			-e "/^GIT_TRACE2_PARENT/d" \
 			-e "/^GIT_/s/=.*//p" |
 		sort
 	EOF
diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
index 71194a3623..ce7574edb1 100755
--- a/t/t0210-trace2-normal.sh
+++ b/t/t0210-trace2-normal.sh
@@ -4,9 +4,9 @@ test_description='test trace2 facility (normal target)'
 . ./test-lib.sh
 
 # Turn off any inherited trace2 settings for this test.
-sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-sane_unset GIT_TR2_BRIEF
-sane_unset GIT_TR2_CONFIG_PARAMS
+sane_unset GIT_TRACE2 GIT_TRACE2_PERF GIT_TRACE2_EVENT
+sane_unset GIT_TRACE2_BRIEF
+sane_unset GIT_TRACE2_CONFIG_PARAMS
 
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
@@ -27,12 +27,12 @@ V=$(git version | sed -e 's/^git version //') && export V
 # to whatever filtering that target decides to do).
 # This script tests the normal target in isolation.
 #
-# Defer setting GIT_TR2 until the actual command line we want to test
+# Defer setting GIT_TRACE2 until the actual command line we want to test
 # because hidden git and test-tool commands run by the test harness
 # can contaminate our output.
 
 # Enable "brief" feature which turns off "<clock> <file>:<line> " prefix.
-GIT_TR2_BRIEF=1 && export GIT_TR2_BRIEF
+GIT_TRACE2_BRIEF=1 && export GIT_TRACE2_BRIEF
 
 # Basic tests of the trace2 normal stream.  Since this stream is used
 # primarily with printf-style debugging/tracing, we do limited testing
@@ -54,7 +54,7 @@ GIT_TR2_BRIEF=1 && export GIT_TR2_BRIEF
 
 test_expect_success 'normal stream, return code 0' '
 	test_when_finished "rm trace.normal actual expect" &&
-	GIT_TR2="$(pwd)/trace.normal" test-tool trace2 001return 0 &&
+	GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -68,7 +68,7 @@ test_expect_success 'normal stream, return code 0' '
 
 test_expect_success 'normal stream, return code 1' '
 	test_when_finished "rm trace.normal actual expect" &&
-	test_must_fail env GIT_TR2="$(pwd)/trace.normal" test-tool trace2 001return 1 &&
+	test_must_fail env GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 001return 1 &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -83,7 +83,7 @@ test_expect_success 'normal stream, return code 1' '
 test_expect_success 'automatic filename' '
 	test_when_finished "rm -r traces actual expect" &&
 	mkdir traces &&
-	GIT_TR2="$(pwd)/traces" test-tool trace2 001return 0 &&
+	GIT_TRACE2="$(pwd)/traces" test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <"$(ls traces/*)" >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -101,7 +101,7 @@ test_expect_success 'automatic filename' '
 
 test_expect_success 'normal stream, exit code 0' '
 	test_when_finished "rm trace.normal actual expect" &&
-	GIT_TR2="$(pwd)/trace.normal" test-tool trace2 002exit 0 &&
+	GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 002exit 0 &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -115,7 +115,7 @@ test_expect_success 'normal stream, exit code 0' '
 
 test_expect_success 'normal stream, exit code 1' '
 	test_when_finished "rm trace.normal actual expect" &&
-	test_must_fail env GIT_TR2="$(pwd)/trace.normal" test-tool trace2 002exit 1 &&
+	test_must_fail env GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 002exit 1 &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -133,7 +133,7 @@ test_expect_success 'normal stream, exit code 1' '
 
 test_expect_success 'normal stream, error event' '
 	test_when_finished "rm trace.normal actual expect" &&
-	GIT_TR2="$(pwd)/trace.normal" test-tool trace2 003error "hello world" "this is a test" &&
+	GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 003error "hello world" "this is a test" &&
 	perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
 	cat >expect <<-EOF &&
 		version $V
@@ -147,7 +147,7 @@ test_expect_success 'normal stream, error event' '
 	test_cmp expect actual
 '
 
-sane_unset GIT_TR2_BRIEF
+sane_unset GIT_TRACE2_BRIEF
 
 # Now test without environment variables and get all Trace2 settings
 # from the global config.
diff --git a/t/t0211-trace2-perf.sh b/t/t0211-trace2-perf.sh
index b501e867af..2c3ad6e8c1 100755
--- a/t/t0211-trace2-perf.sh
+++ b/t/t0211-trace2-perf.sh
@@ -4,9 +4,9 @@ test_description='test trace2 facility (perf target)'
 . ./test-lib.sh
 
 # Turn off any inherited trace2 settings for this test.
-sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-sane_unset GIT_TR2_PERF_BRIEF
-sane_unset GIT_TR2_CONFIG_PARAMS
+sane_unset GIT_TRACE2 GIT_TRACE2_PERF GIT_TRACE2_EVENT
+sane_unset GIT_TRACE2_PERF_BRIEF
+sane_unset GIT_TRACE2_CONFIG_PARAMS
 
 # Add t/helper directory to PATH so that we can use a relative
 # path to run nested instances of test-tool.exe (see 004child).
@@ -27,13 +27,13 @@ V=$(git version | sed -e 's/^git version //') && export V
 # to whatever filtering that target decides to do).
 # Test each target independently.
 #
-# Defer setting GIT_TR2_PERF until the actual command we want to
+# Defer setting GIT_TRACE2_PERF until the actual command we want to
 # test because hidden git and test-tool commands in the test
 # harness can contaminate our output.
 
 # Enable "brief" feature which turns off the prefix:
 #     "<clock> <file>:<line> | <nr_parents> | "
-GIT_TR2_PERF_BRIEF=1 && export GIT_TR2_PERF_BRIEF
+GIT_TRACE2_PERF_BRIEF=1 && export GIT_TRACE2_PERF_BRIEF
 
 # Repeat some of the t0210 tests using the perf target stream instead of
 # the normal stream.
@@ -46,7 +46,7 @@ GIT_TR2_PERF_BRIEF=1 && export GIT_TR2_PERF_BRIEF
 
 test_expect_success 'perf stream, return code 0' '
 	test_when_finished "rm trace.perf actual expect" &&
-	GIT_TR2_PERF="$(pwd)/trace.perf" test-tool trace2 001return 0 &&
+	GIT_TRACE2_PERF="$(pwd)/trace.perf" test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
@@ -60,7 +60,7 @@ test_expect_success 'perf stream, return code 0' '
 
 test_expect_success 'perf stream, return code 1' '
 	test_when_finished "rm trace.perf actual expect" &&
-	test_must_fail env GIT_TR2_PERF="$(pwd)/trace.perf" test-tool trace2 001return 1 &&
+	test_must_fail env GIT_TRACE2_PERF="$(pwd)/trace.perf" test-tool trace2 001return 1 &&
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
@@ -78,7 +78,7 @@ test_expect_success 'perf stream, return code 1' '
 
 test_expect_success 'perf stream, error event' '
 	test_when_finished "rm trace.perf actual expect" &&
-	GIT_TR2_PERF="$(pwd)/trace.perf" test-tool trace2 003error "hello world" "this is a test" &&
+	GIT_TRACE2_PERF="$(pwd)/trace.perf" test-tool trace2 003error "hello world" "this is a test" &&
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
@@ -124,7 +124,7 @@ test_expect_success 'perf stream, error event' '
 
 test_expect_success 'perf stream, child processes' '
 	test_when_finished "rm trace.perf actual expect" &&
-	GIT_TR2_PERF="$(pwd)/trace.perf" test-tool trace2 004child test-tool trace2 004child test-tool trace2 001return 0 &&
+	GIT_TRACE2_PERF="$(pwd)/trace.perf" test-tool trace2 004child test-tool trace2 004child test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <trace.perf >actual &&
 	cat >expect <<-EOF &&
 		d0|main|version|||||$V
@@ -150,7 +150,7 @@ test_expect_success 'perf stream, child processes' '
 	test_cmp expect actual
 '
 
-sane_unset GIT_TR2_PERF_BRIEF
+sane_unset GIT_TRACE2_PERF_BRIEF
 
 # Now test without environment variables and get all Trace2 settings
 # from the global config.
diff --git a/t/t0212-trace2-event.sh b/t/t0212-trace2-event.sh
index 59adae8123..ff5b9cc729 100755
--- a/t/t0212-trace2-event.sh
+++ b/t/t0212-trace2-event.sh
@@ -4,9 +4,9 @@ test_description='test trace2 facility'
 . ./test-lib.sh
 
 # Turn off any inherited trace2 settings for this test.
-sane_unset GIT_TR2 GIT_TR2_PERF GIT_TR2_EVENT
-sane_unset GIT_TR2_BARE
-sane_unset GIT_TR2_CONFIG_PARAMS
+sane_unset GIT_TRACE2 GIT_TRACE2_PERF GIT_TRACE2_EVENT
+sane_unset GIT_TRACE2_BARE
+sane_unset GIT_TRACE2_CONFIG_PARAMS
 
 perl -MJSON::PP -e 0 >/dev/null 2>&1 && test_set_prereq JSON_PP
 
@@ -29,7 +29,7 @@ V=$(git version | sed -e 's/^git version //') && export V
 # to whatever filtering that target decides to do).
 # Test each target independently.
 #
-# Defer setting GIT_TR2_PERF until the actual command we want to
+# Defer setting GIT_TRACE2_PERF until the actual command we want to
 # test because hidden git and test-tool commands in the test
 # harness can contaminate our output.
 
@@ -42,7 +42,7 @@ V=$(git version | sed -e 's/^git version //') && export V
 
 test_expect_success JSON_PP 'event stream, error event' '
 	test_when_finished "rm trace.event actual expect" &&
-	GIT_TR2_EVENT="$(pwd)/trace.event" test-tool trace2 003error "hello world" "this is a test" &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool trace2 003error "hello world" "this is a test" &&
 	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
 	sed -e "s/^|//" >expect <<-EOF &&
 	|VAR1 = {
@@ -79,7 +79,7 @@ test_expect_success JSON_PP 'event stream, error event' '
 
 test_expect_success JSON_PP 'event stream, return code 0' '
 	test_when_finished "rm trace.event actual expect" &&
-	GIT_TR2_EVENT="$(pwd)/trace.event" test-tool trace2 004child test-tool trace2 004child test-tool trace2 001return 0 &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool trace2 004child test-tool trace2 004child test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
 	sed -e "s/^|//" >expect <<-EOF &&
 	|VAR1 = {
@@ -168,7 +168,7 @@ test_expect_success JSON_PP 'event stream, list config' '
 	test_when_finished "rm trace.event actual expect" &&
 	git config --local t0212.abc 1 &&
 	git config --local t0212.def "hello world" &&
-	GIT_TR2_EVENT="$(pwd)/trace.event" GIT_TR2_CONFIG_PARAMS="t0212.*" test-tool trace2 001return 0 &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" GIT_TRACE2_CONFIG_PARAMS="t0212.*" test-tool trace2 001return 0 &&
 	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
 	sed -e "s/^|//" >expect <<-EOF &&
 	|VAR1 = {
@@ -201,7 +201,7 @@ test_expect_success JSON_PP 'event stream, list config' '
 
 test_expect_success JSON_PP 'basic trace2_data' '
 	test_when_finished "rm trace.event actual expect" &&
-	GIT_TR2_EVENT="$(pwd)/trace.event" test-tool trace2 006data test_category k1 v1 test_category k2 v2 &&
+	GIT_TRACE2_EVENT="$(pwd)/trace.event" test-tool trace2 006data test_category k1 v1 test_category k2 v2 &&
 	perl "$TEST_DIRECTORY/t0212/parse_events.perl" <trace.event >actual &&
 	sed -e "s/^|//" >expect <<-EOF &&
 	|VAR1 = {
diff --git a/t/t0212/parse_events.perl b/t/t0212/parse_events.perl
index a2776ba216..6584bb5634 100644
--- a/t/t0212/parse_events.perl
+++ b/t/t0212/parse_events.perl
@@ -26,7 +26,7 @@ use Getopt::Long;
 
 # The version of the trace2 event target format that we understand.
 # This is reported in the 'version' event in the 'evt' field.
-# It comes from the GIT_TR2_EVENT_VERSION macro in trace2/tr2_tgt_event.c
+# It comes from the GIT_TRACE2_EVENT_VERSION macro in trace2/tr2_tgt_event.c
 my $evt_version = '1';
 
 my $show_children = 1;
diff --git a/trace2.h b/trace2.h
index f189ef5984..050bf3c8c1 100644
--- a/trace2.h
+++ b/trace2.h
@@ -130,7 +130,7 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
  * list of patterns configured important.  For example:
  *     git config --system trace2.configParams 'core.*,remote.*.url'
  * or:
- *     GIT_TR2_CONFIG_PARAMS=core.*,remote.*.url"
+ *     GIT_TRACE2_CONFIG_PARAMS=core.*,remote.*.url"
  *
  * Note: this routine does a read-only iteration on the config data
  * (using read_early_config()), so it must not be called until enough
diff --git a/trace2/tr2_cmd_name.c b/trace2/tr2_cmd_name.c
index e999592b4c..dd313204f5 100644
--- a/trace2/tr2_cmd_name.c
+++ b/trace2/tr2_cmd_name.c
@@ -1,7 +1,7 @@
 #include "cache.h"
 #include "trace2/tr2_cmd_name.h"
 
-#define TR2_ENVVAR_PARENT_NAME "GIT_TR2_PARENT_NAME"
+#define TR2_ENVVAR_PARENT_NAME "GIT_TRACE2_PARENT_NAME"
 
 static struct strbuf tr2cmdname_hierarchy = STRBUF_INIT;
 
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 5047095478..6948fd4108 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -2,7 +2,7 @@
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
 
-#define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
+#define TR2_ENVVAR_PARENT_SID "GIT_TRACE2_PARENT_SID"
 
 static struct strbuf tr2sid_buf = STRBUF_INIT;
 static int tr2sid_nr_git_parents;
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
index 9025b86303..5958cfc424 100644
--- a/trace2/tr2_sysenv.c
+++ b/trace2/tr2_sysenv.c
@@ -21,33 +21,33 @@ struct tr2_sysenv_entry {
  * The strings in this table are constant and must match the published
  * config and environment variable names as described in the documentation.
  *
- * We do not define entries for the GIT_TR2_PARENT_* environment
+ * We do not define entries for the GIT_TRACE2_PARENT_* environment
  * variables because they are transient and used to pass information
  * from parent to child git processes, rather than settings.
  */
 /* clang-format off */
 static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
-	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TR2_CONFIG_PARAMS",
+	[TR2_SYSENV_CFG_PARAM]     = { "GIT_TRACE2_CONFIG_PARAMS",
 				       "trace2.configparams" },
 
-	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TR2_DST_DEBUG",
+	[TR2_SYSENV_DST_DEBUG]     = { "GIT_TRACE2_DST_DEBUG",
 				       "trace2.destinationdebug" },
 
-	[TR2_SYSENV_NORMAL]        = { "GIT_TR2",
+	[TR2_SYSENV_NORMAL]        = { "GIT_TRACE2",
 				       "trace2.normaltarget" },
-	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TR2_BRIEF",
+	[TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TRACE2_BRIEF",
 				       "trace2.normalbrief" },
 
-	[TR2_SYSENV_EVENT]         = { "GIT_TR2_EVENT",
+	[TR2_SYSENV_EVENT]         = { "GIT_TRACE2_EVENT",
 				       "trace2.eventtarget" },
-	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TR2_EVENT_BRIEF",
+	[TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TRACE2_EVENT_BRIEF",
 				       "trace2.eventbrief" },
-	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TR2_EVENT_NESTING",
+	[TR2_SYSENV_EVENT_NESTING] = { "GIT_TRACE2_EVENT_NESTING",
 				       "trace2.eventnesting" },
 
-	[TR2_SYSENV_PERF]          = { "GIT_TR2_PERF",
+	[TR2_SYSENV_PERF]          = { "GIT_TRACE2_PERF",
 				       "trace2.perftarget" },
-	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TR2_PERF_BRIEF",
+	[TR2_SYSENV_PERF_BRIEF]    = { "GIT_TRACE2_PERF_BRIEF",
 				       "trace2.perfbrief" },
 };
 /* clang-format on */
diff --git a/trace2/tr2_sysenv.h b/trace2/tr2_sysenv.h
index 369b20bd87..8dd82a7a56 100644
--- a/trace2/tr2_sysenv.h
+++ b/trace2/tr2_sysenv.h
@@ -7,7 +7,7 @@
  *
  * Note that this set does not contain any of the transient
  * environment variables used to pass information from parent
- * to child git processes, such "GIT_TR2_PARENT_SID".
+ * to child git processes, such "GIT_TRACE2_PARENT_SID".
  */
 enum tr2_sysenv_variable {
 	TR2_SYSENV_CFG_PARAM = 0,