view tests/test-bisect.t @ 40021:c537144fdbef

wireprotov2: support response caching

One of the things I've learned from managing VCS servers over the
years is that they are hard to scale. It is well known that some
companies have very beefy (read: very expensive) servers to power
their VCS needs. It is also known that specialized servers for
various VCS exist in order to facilitate scaling servers. (Mercurial
is in this boat.)

One of the aspects that make a VCS server hard to scale is the
high CPU load incurred by constant client clone/pull operations.

To alleviate the scaling pain associated with data retrieval
operations, I want to integrate caching into the Mercurial wire
protocol server as robustly as possible such that servers can
aggressively cache responses and defer as much server load as
possible.

This commit represents the initial implementation of a general
caching layer in wire protocol version 2.

We define a new interface and behavior for a wire protocol cacher
in repository.py. (This is probably where a reviewer should look
first to understand what is going on.)

The bulk of the added code is in wireprotov2server.py, where we
define how a command can opt in to being cached and integrate
caching into command dispatching.

From a very high-level:

* A command can declare itself as cacheable by providing a callable
  that can be used to derive a cache key.
* At dispatch time, if a command is cacheable, we attempt to
  construct a cacher and use it for serving the request and/or
  caching the request.
* The dispatch layer handles the bulk of the business logic for
  caching, making cachers mostly "dumb content stores."
* The mechanism for invalidating cached entries (one of the harder
  parts about caching in general) is by varying the cache key when
  state changes. As such, cachers don't need to be concerned with
  cache invalidation.

Initially, we've hooked up support for caching "manifestdata" and
"filedata" commands. These are the simplest to cache, as they should
be immutable over time. Caching of commands related to changeset
data is a bit harder (because cache validation is impacted by
changes to bookmarks, phases, etc). This will be implemented later.
(Strictly speaking, censoring a file should invalidate caches. I've
added an inline TODO to track this edge case.)

To prove it works, this commit implements a test-only extension
providing in-memory caching backed by an lrucachedict. A new test
showing this extension behaving properly is added. FWIW, the
cacher is ~50 lines of code, demonstrating the relative ease with
which a cache can be added to a server.

While the test cacher is not suitable for production workloads, just
for kicks I performed a clone of just the changeset and manifest data
for the mozilla-unified repository. With a fully warmed cache (of just
the manifest data since changeset data is not cached), server-side
CPU usage dropped from ~73s to ~28s. That's pretty significant and
demonstrates the potential that response caching has on server
scalability!

Differential Revision: https://phab.mercurial-scm.org/D4773

  $ hg init


committing changes

  $ count=0
  $ echo > a
  $ while test $count -lt 32 ; do
  >     echo 'a' >> a
  >     test $count -eq 0 && hg add
  >     hg ci -m "msg $count" -d "$count 0"
  >     count=`expr $count + 1`
  > done
  adding a


  $ hg log
  changeset:   31:58c80a7c8a40
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:31 1970 +0000
  summary:     msg 31
  
  changeset:   30:ed2d2f24b11c
  user:        test
  date:        Thu Jan 01 00:00:30 1970 +0000
  summary:     msg 30
  
  changeset:   29:b5bd63375ab9
  user:        test
  date:        Thu Jan 01 00:00:29 1970 +0000
  summary:     msg 29
  
  changeset:   28:8e0c2264c8af
  user:        test
  date:        Thu Jan 01 00:00:28 1970 +0000
  summary:     msg 28
  
  changeset:   27:288867a866e9
  user:        test
  date:        Thu Jan 01 00:00:27 1970 +0000
  summary:     msg 27
  
  changeset:   26:3efc6fd51aeb
  user:        test
  date:        Thu Jan 01 00:00:26 1970 +0000
  summary:     msg 26
  
  changeset:   25:02a84173a97a
  user:        test
  date:        Thu Jan 01 00:00:25 1970 +0000
  summary:     msg 25
  
  changeset:   24:10e0acd3809e
  user:        test
  date:        Thu Jan 01 00:00:24 1970 +0000
  summary:     msg 24
  
  changeset:   23:5ec79163bff4
  user:        test
  date:        Thu Jan 01 00:00:23 1970 +0000
  summary:     msg 23
  
  changeset:   22:06c7993750ce
  user:        test
  date:        Thu Jan 01 00:00:22 1970 +0000
  summary:     msg 22
  
  changeset:   21:e5db6aa3fe2a
  user:        test
  date:        Thu Jan 01 00:00:21 1970 +0000
  summary:     msg 21
  
  changeset:   20:7128fb4fdbc9
  user:        test
  date:        Thu Jan 01 00:00:20 1970 +0000
  summary:     msg 20
  
  changeset:   19:52798545b482
  user:        test
  date:        Thu Jan 01 00:00:19 1970 +0000
  summary:     msg 19
  
  changeset:   18:86977a90077e
  user:        test
  date:        Thu Jan 01 00:00:18 1970 +0000
  summary:     msg 18
  
  changeset:   17:03515f4a9080
  user:        test
  date:        Thu Jan 01 00:00:17 1970 +0000
  summary:     msg 17
  
  changeset:   16:a2e6ea4973e9
  user:        test
  date:        Thu Jan 01 00:00:16 1970 +0000
  summary:     msg 16
  
  changeset:   15:e7fa0811edb0
  user:        test
  date:        Thu Jan 01 00:00:15 1970 +0000
  summary:     msg 15
  
  changeset:   14:ce8f0998e922
  user:        test
  date:        Thu Jan 01 00:00:14 1970 +0000
  summary:     msg 14
  
  changeset:   13:9d7d07bc967c
  user:        test
  date:        Thu Jan 01 00:00:13 1970 +0000
  summary:     msg 13
  
  changeset:   12:1941b52820a5
  user:        test
  date:        Thu Jan 01 00:00:12 1970 +0000
  summary:     msg 12
  
  changeset:   11:7b4cd9578619
  user:        test
  date:        Thu Jan 01 00:00:11 1970 +0000
  summary:     msg 11
  
  changeset:   10:7c5eff49a6b6
  user:        test
  date:        Thu Jan 01 00:00:10 1970 +0000
  summary:     msg 10
  
  changeset:   9:eb44510ef29a
  user:        test
  date:        Thu Jan 01 00:00:09 1970 +0000
  summary:     msg 9
  
  changeset:   8:453eb4dba229
  user:        test
  date:        Thu Jan 01 00:00:08 1970 +0000
  summary:     msg 8
  
  changeset:   7:03750880c6b5
  user:        test
  date:        Thu Jan 01 00:00:07 1970 +0000
  summary:     msg 7
  
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  
  changeset:   5:7874a09ea728
  user:        test
  date:        Thu Jan 01 00:00:05 1970 +0000
  summary:     msg 5
  
  changeset:   4:9b2ba8336a65
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     msg 4
  
  changeset:   3:b53bea5e2fcb
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     msg 3
  
  changeset:   2:db07c04beaca
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     msg 2
  
  changeset:   1:5cd978ea5149
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     msg 1
  
  changeset:   0:b99c7b9c8e11
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     msg 0
  

  $ hg up -C
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

bisect test

  $ hg bisect -r
  $ hg bisect -b
  $ hg status -v
  # The repository is in an unfinished *bisect* state.
  
  # To mark the changeset good:    hg bisect --good
  # To mark the changeset bad:     hg bisect --bad
  # To abort:                      hg bisect --reset
  
  $ hg status -v --config commands.status.skipstates=bisect
  $ hg summary
  parent: 31:58c80a7c8a40 tip
   msg 31
  branch: default
  commit: (clean)
  update: (current)
  phases: 32 draft
  $ hg bisect -g 1
  Testing changeset 16:a2e6ea4973e9 (30 changesets remaining, ~4 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 23:5ec79163bff4 (15 changesets remaining, ~3 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

skip

  $ hg bisect -s
  Testing changeset 24:10e0acd3809e (15 changesets remaining, ~3 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 27:288867a866e9 (7 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 29:b5bd63375ab9 (4 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -b
  Testing changeset 28:8e0c2264c8af (2 changesets remaining, ~1 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  The first bad revision is:
  changeset:   29:b5bd63375ab9
  user:        test
  date:        Thu Jan 01 00:00:29 1970 +0000
  summary:     msg 29
  

mark revsets instead of single revs

  $ hg bisect -r
  $ hg bisect -b "0::3"
  $ hg bisect -s "13::16"
  $ hg bisect -g "26::tip"
  Testing changeset 12:1941b52820a5 (23 changesets remaining, ~4 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat .hg/bisect.state
  bad b99c7b9c8e11558adef3fad9af211c58d46f325b
  bad 5cd978ea51499179507ee7b6f340d2dbaa401185
  bad db07c04beaca44cf24832541e7f4a2346a95275b
  bad b53bea5e2fcb30d3e00bd3409507a5659ce0fd8b
  current 1941b52820a544549596820a8ae006842b0e2c64
  good 3efc6fd51aeb8594398044c6c846ca59ae021203
  good 288867a866e9adb7a29880b66936c874b80f4651
  good 8e0c2264c8af790daf3585ada0669d93dee09c83
  good b5bd63375ab9a290419f2024b7f4ee9ea7ce90a8
  good ed2d2f24b11c368fa8aa0da9f4e1db580abade59
  good 58c80a7c8a4025a94cedaf7b4a4e3124e8909a96
  skip 9d7d07bc967ca98ad0600c24953fd289ad5fa991
  skip ce8f0998e922c179e80819d5066fbe46e2998784
  skip e7fa0811edb063f6319531f0d0a865882138e180
  skip a2e6ea4973e9196ddd3386493b0c214b41fd97d3

bisect reverse test

  $ hg bisect -r
  $ hg bisect -b null
  $ hg bisect -g tip
  Testing changeset 15:e7fa0811edb0 (32 changesets remaining, ~5 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 7:03750880c6b5 (16 changesets remaining, ~4 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

skip

  $ hg bisect -s
  Testing changeset 6:a3d5c6fdf0d3 (16 changesets remaining, ~4 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 2:db07c04beaca (7 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  Testing changeset 0:b99c7b9c8e11 (3 changesets remaining, ~1 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -b
  Testing changeset 1:5cd978ea5149 (2 changesets remaining, ~1 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  The first good revision is:
  changeset:   1:5cd978ea5149
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     msg 1
  

  $ hg bisect -r
  $ hg bisect -g tip
  $ hg bisect -b tip
  abort: inconsistent state, 31:58c80a7c8a40 is good and bad
  [255]

  $ hg bisect -r
  $ hg bisect -g null
  $ hg bisect -bU tip
  Testing changeset 15:e7fa0811edb0 (32 changesets remaining, ~5 tests)
  $ hg id
  5cd978ea5149


Issue1228: hg bisect crashes when you skip the last rev in bisection
Issue1182: hg bisect exception

  $ hg bisect -r
  $ hg bisect -b 4
  $ hg bisect -g 0
  Testing changeset 2:db07c04beaca (4 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 1:5cd978ea5149 (4 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 3:b53bea5e2fcb (4 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Due to skipped revisions, the first bad revision could be any of:
  changeset:   1:5cd978ea5149
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     msg 1
  
  changeset:   2:db07c04beaca
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     msg 2
  
  changeset:   3:b53bea5e2fcb
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     msg 3
  
  changeset:   4:9b2ba8336a65
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     msg 4
  


reproduce non converging bisect, issue1182

  $ hg bisect -r
  $ hg bisect -g 0
  $ hg bisect -b 2
  Testing changeset 1:5cd978ea5149 (2 changesets remaining, ~1 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Due to skipped revisions, the first bad revision could be any of:
  changeset:   1:5cd978ea5149
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     msg 1
  
  changeset:   2:db07c04beaca
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     msg 2
  


test no action

  $ hg bisect -r
  $ hg bisect
  abort: cannot bisect (no known good revisions)
  [255]


reproduce AssertionError, issue1445

  $ hg bisect -r
  $ hg bisect -b 6
  $ hg bisect -g 0
  Testing changeset 3:b53bea5e2fcb (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 2:db07c04beaca (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 4:9b2ba8336a65 (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 1:5cd978ea5149 (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -s
  Testing changeset 5:7874a09ea728 (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect -g
  The first bad revision is:
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  
  $ hg log -r "bisect(good)"
  changeset:   0:b99c7b9c8e11
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     msg 0
  
  changeset:   5:7874a09ea728
  user:        test
  date:        Thu Jan 01 00:00:05 1970 +0000
  summary:     msg 5
  
  $ hg log -r "bisect(bad)"
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  
  $ hg log -r "bisect(current)"
  changeset:   5:7874a09ea728
  user:        test
  date:        Thu Jan 01 00:00:05 1970 +0000
  summary:     msg 5
  
  $ hg log -r "bisect(skip)"
  changeset:   1:5cd978ea5149
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     msg 1
  
  changeset:   2:db07c04beaca
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     msg 2
  
  changeset:   3:b53bea5e2fcb
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     msg 3
  
  changeset:   4:9b2ba8336a65
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     msg 4
  

test legacy bisected() keyword

  $ hg log -r "bisected(bad)"
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  

  $ set +e

test invalid command
assuming that the shell returns 127 if command not found ...

  $ hg bisect -r
  $ hg bisect --command 'exit 127'
  abort: failed to execute exit 127
  [255]


test bisecting command

  $ cat > script.py <<EOF
  > #!$PYTHON
  > from __future__ import absolute_import
  > import sys
  > from mercurial import hg, ui as uimod
  > repo = hg.repository(uimod.ui.load(), b'.')
  > if repo[b'.'].rev() < 6:
  >     sys.exit(1)
  > EOF
  $ chmod +x script.py
  $ hg bisect -r
  $ hg up -qr tip
  $ hg bisect --command "\"$PYTHON\" \"$TESTTMP/script.py\" and some parameters"
  changeset 31:58c80a7c8a40: good
  abort: cannot bisect (no known bad revisions)
  [255]
  $ hg up -qr 0
  $ hg bisect --command "\"$PYTHON\" \"$TESTTMP/script.py\" and some parameters"
  changeset 0:b99c7b9c8e11: bad
  changeset 15:e7fa0811edb0: good
  changeset 7:03750880c6b5: good
  changeset 3:b53bea5e2fcb: bad
  changeset 5:7874a09ea728: bad
  changeset 6:a3d5c6fdf0d3: good
  The first good revision is:
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  


test bisecting via a command without updating the working dir, and
ensure that the bisect state file is updated before running a test
command

  $ hg update null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cat > script.sh <<'EOF'
  > #!/bin/sh
  > test -n "$HG_NODE" || (echo HG_NODE missing; exit 127)
  > current="`hg log -r \"bisect(current)\" --template {node}`"
  > test "$current" = "$HG_NODE" || (echo current is bad: $current; exit 127)
  > rev="`hg log -r $HG_NODE --template {rev}`"
  > test "$rev" -ge 6
  > EOF
  $ chmod +x script.sh
  $ hg bisect -r
  $ hg bisect --good tip --noupdate
  $ hg bisect --bad 0 --noupdate
  Testing changeset 15:e7fa0811edb0 (31 changesets remaining, ~4 tests)
  $ hg bisect --command "sh \"$TESTTMP/script.sh\" and some params" --noupdate
  changeset 15:e7fa0811edb0: good
  changeset 7:03750880c6b5: good
  changeset 3:b53bea5e2fcb: bad
  changeset 5:7874a09ea728: bad
  changeset 6:a3d5c6fdf0d3: good
  The first good revision is:
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  

ensure that we still don't have a working dir

  $ hg parents


test the same case, this time with updating

  $ cat > script.sh <<'EOF'
  > #!/bin/sh
  > test -n "$HG_NODE" || (echo HG_NODE missing; exit 127)
  > current="`hg log -r \"bisect(current)\" --template {node}`"
  > test "$current" = "$HG_NODE" || (echo current is bad: $current; exit 127)
  > rev="`hg log -r . --template {rev}`"
  > test "$rev" -ge 6
  > EOF
  $ chmod +x script.sh
  $ hg bisect -r
  $ hg up -qr tip
  $ hg bisect --command "sh \"$TESTTMP/script.sh\" and some params"
  changeset 31:58c80a7c8a40: good
  abort: cannot bisect (no known bad revisions)
  [255]
  $ hg up -qr 0
  $ hg bisect --command "sh \"$TESTTMP/script.sh\" and some params"
  changeset 0:b99c7b9c8e11: bad
  changeset 15:e7fa0811edb0: good
  changeset 7:03750880c6b5: good
  changeset 3:b53bea5e2fcb: bad
  changeset 5:7874a09ea728: bad
  changeset 6:a3d5c6fdf0d3: good
  The first good revision is:
  changeset:   6:a3d5c6fdf0d3
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     msg 6
  
  $ hg graft -q 15
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  abort: unresolved conflicts, can't continue
  (use 'hg resolve' and 'hg graft --continue')
  [255]
  $ hg bisect --reset
  $ hg up -C .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Check that bisect does not break on obsolete changesets
=========================================================

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > evolution.createmarkers=True
  > EOF

tip is obsolete
---------------------

  $ hg debugobsolete `hg id --debug -i -r tip`
  obsoleted 1 changesets
  $ hg bisect --reset
  $ hg bisect --good 15
  $ hg bisect --bad 30
  Testing changeset 22:06c7993750ce (15 changesets remaining, ~3 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect --command true
  changeset 22:06c7993750ce: good
  changeset 26:3efc6fd51aeb: good
  changeset 28:8e0c2264c8af: good
  changeset 29:b5bd63375ab9: good
  The first bad revision is:
  changeset:   30:ed2d2f24b11c
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:30 1970 +0000
  summary:     msg 30
  

Changeset in the bad:good range is obsolete
---------------------------------------------

  $ hg up 30
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 'a' >> a
  $ hg ci -m "msg 32" -d "32 0"
  $ hg bisect --reset
  $ hg bisect --good .
  $ hg bisect --bad 25
  Testing changeset 28:8e0c2264c8af (6 changesets remaining, ~2 tests)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg bisect --command true
  changeset 28:8e0c2264c8af: good
  changeset 26:3efc6fd51aeb: good
  The first good revision is:
  changeset:   26:3efc6fd51aeb
  user:        test
  date:        Thu Jan 01 00:00:26 1970 +0000
  summary:     msg 26
  
Test the validation message when exclusive options are used:

  $ hg bisect -r
  $ hg bisect -b -c false
  abort: --bad and --command are incompatible
  [255]
  $ hg bisect -b -e
  abort: --bad and --extend are incompatible
  [255]
  $ hg bisect -b -g
  abort: --bad and --good are incompatible
  [255]
  $ hg bisect -b -r
  abort: --bad and --reset are incompatible
  [255]
  $ hg bisect -b -s
  abort: --bad and --skip are incompatible
  [255]
  $ hg bisect -c false -e
  abort: --command and --extend are incompatible
  [255]
  $ hg bisect -c false -g
  abort: --command and --good are incompatible
  [255]
  $ hg bisect -c false -r
  abort: --command and --reset are incompatible
  [255]
  $ hg bisect -c false -s
  abort: --command and --skip are incompatible
  [255]
  $ hg bisect -e -g
  abort: --extend and --good are incompatible
  [255]
  $ hg bisect -e -r
  abort: --extend and --reset are incompatible
  [255]
  $ hg bisect -e -s
  abort: --extend and --skip are incompatible
  [255]
  $ hg bisect -g -r
  abort: --good and --reset are incompatible
  [255]
  $ hg bisect -g -s
  abort: --good and --skip are incompatible
  [255]
  $ hg bisect -r -s
  abort: --reset and --skip are incompatible
  [255]