annotate tests/test-ssh.t @ 37533:df4985497986

wireproto: implement capabilities for wire protocol v2

The capabilities mechanism for wire protocol version 2 represents a
clean break from version 1.

Instead of effectively exchanging a set of capabilities, we're
exchanging a rich data structure.

This data structure currently contains information about
every available command, including its accepted arguments. It also
contains information about supported compression formats.

Exposing information about supported commands will allow clients
to automatically generate bindings to the server. Clients will be
able to do things like detect when they are attempting to run a
command that isn't known to the server. Exposing the required
permissions to run a command can be used by clients to determine if
they have privileges to call a command before actually calling it.
We could potentially even have clients send credentials
preemptively without waiting for the server to deny the command
request. Lots of potential here.

The data returned by this command will likely evolve heavily. So we
shouldn't bikeshed the implementation just yet.

Differential Revision: https://phab.mercurial-scm.org/D3200

#testcases sshv1 sshv2

#if sshv2
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > sshpeer.advertise-v2 = true
  > sshserver.support-v2 = true
  > EOF
#endif

This test tries to exercise the ssh functionality with a dummy script

creating 'remote' repo

  $ hg init remote
  $ cd remote
  $ echo this > foo
  $ echo this > fooO
  $ hg ci -A -m "init" foo fooO

insert a closed branch (issue4428)

  $ hg up null
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch closed
  marked working directory as branch closed
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -mc0
  $ hg ci --close-branch -mc1
  $ hg up -q default

configure for serving

  $ cat <<EOF > .hg/hgrc
  > [server]
  > uncompressed = True
  > 
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup-in-remote 0 ../dummylog"
  > EOF
  $ cd ..

repo not found error

  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/nonexistent local
  remote: abort: repository nonexistent not found!
  abort: no suitable response from remote hg!
  [255]

non-existent absolute path

  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/nonexistent local
  remote: abort: repository $TESTTMP/nonexistent not found!
  abort: no suitable response from remote hg!
  [255]

clone remote via stream

#if no-reposimplestore

  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --stream ssh://user@dummy/remote local-stream
  streaming all changes
  4 files to transfer, 602 bytes of data
  transferred 602 bytes in * seconds (*) (glob)
  searching for changes
  no changes found
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local-stream
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 3 changesets, 2 total revisions
  $ hg branches
  default                        0:1160648e36ce
  $ cd ..

clone bookmarks via stream

  $ hg -R local-stream book mybook
  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --stream ssh://user@dummy/local-stream stream2
  streaming all changes
  4 files to transfer, 602 bytes of data
  transferred 602 bytes in * seconds (*) (glob)
  searching for changes
  no changes found
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd stream2
  $ hg book
     mybook                    0:1160648e36ce
  $ cd ..
  $ rm -rf local-stream stream2

#endif

clone remote via pull

  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  new changesets 1160648e36ce:ad076bfb429d
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

verify

  $ cd local
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 3 changesets, 2 total revisions
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup-in-local 0 ../dummylog"
  > EOF

empty default pull

  $ hg paths
  default = ssh://user@dummy/remote
  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\""
  pulling from ssh://user@dummy/remote
  searching for changes
  no changes found

pull from wrong ssh URL

  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/doesnotexist
  pulling from ssh://user@dummy/doesnotexist
  remote: abort: repository doesnotexist not found!
  abort: no suitable response from remote hg!
  [255]

local change

  $ echo bleah > foo
  $ hg ci -m "add"

updating rc

  $ echo "default-push = ssh://user@dummy/remote" >> .hg/hgrc
  $ echo "[ui]" >> .hg/hgrc
  $ echo "ssh = \"$PYTHON\" \"$TESTDIR/dummyssh\"" >> .hg/hgrc

find outgoing

  $ hg out ssh://user@dummy/remote
  comparing with ssh://user@dummy/remote
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

find incoming on the remote side

  $ hg incoming -R ../remote -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/local
  comparing with ssh://user@dummy/local
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

find incoming on the remote side (using absolute path)

  $ hg incoming -R ../remote -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" "ssh://user@dummy/`pwd`"
  comparing with ssh://user@dummy/$TESTTMP/local
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

push

  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ cd ../remote

check remote tip

  $ hg tip
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 4 changesets, 3 total revisions
  $ hg cat -r tip foo
  bleah
  $ echo z > z
  $ hg ci -A -m z z
  created new head

test pushkeys and bookmarks

  $ cd ../local
  $ hg debugpushkey --config ui.ssh="\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote namespaces
  bookmarks	
  namespaces	
  phases	
  $ hg book foo -r 0
  $ hg out -B
  comparing with ssh://user@dummy/remote
  searching for changed bookmarks
     foo                       1160648e36ce
  $ hg push -B foo
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  exporting bookmark foo
  [1]
  $ hg debugpushkey --config ui.ssh="\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote bookmarks
  foo	1160648e36cec0054048a7edc4110c6f84fde594
  $ hg book -f foo
  $ hg push --traceback
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  updating bookmark foo
  [1]
  $ hg book -d foo
  $ hg in -B
  comparing with ssh://user@dummy/remote
  searching for changed bookmarks
     foo                       a28a9d1a809c
  $ hg book -f -r 0 foo
  $ hg pull -B foo
  pulling from ssh://user@dummy/remote
  no changes found
  updating bookmark foo
  $ hg book -d foo
  $ hg push -B foo
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  deleting remote bookmark foo
  [1]

a bad, evil hook that prints to stdout

  $ cat <<EOF > $TESTTMP/badhook
  > import sys
  > sys.stdout.write("KABOOM\n")
  > EOF

  $ cat <<EOF > $TESTTMP/badpyhook.py
  > import sys
  > def hook(ui, repo, hooktype, **kwargs):
  >     sys.stdout.write("KABOOM IN PROCESS\n")
  > EOF

  $ cat <<EOF >> ../remote/.hg/hgrc
  > [hooks]
  > changegroup.stdout = $PYTHON $TESTTMP/badhook
  > changegroup.pystdout = python:$TESTTMP/badpyhook.py:hook
  > EOF
  $ echo r > r
  $ hg ci -A -m z r

push should succeed even though it has an unexpected response

  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote has heads on branch 'default' that are not known locally: 6c0482d977a3
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: KABOOM
  remote: KABOOM IN PROCESS
  $ hg -R ../remote heads
  changeset:   5:1383141674ec
  tag:         tip
  parent:      3:a28a9d1a809c
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     z
  
  changeset:   4:6c0482d977a3
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     z
  

clone bookmarks

  $ hg -R ../remote bookmark test
  $ hg -R ../remote bookmarks
   * test                      4:6c0482d977a3
  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote local-bookmarks
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 4 files (+1 heads)
  new changesets 1160648e36ce:1383141674ec
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R local-bookmarks bookmarks
     test                      4:6c0482d977a3

passwords in ssh urls are not supported
(we use a glob here because different Python versions give different
results here)

  $ hg push ssh://user:erroneouspwd@dummy/remote
  pushing to ssh://user:*@dummy/remote (glob)
  abort: password in URL not supported!
  [255]

  $ cd ..

hide outer repo
  $ hg init

Test remote paths with spaces (issue2983):

  $ hg init --ssh "\"$PYTHON\" \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
  $ touch "$TESTTMP/a repo/test"
  $ hg -R 'a repo' commit -A -m "test"
  adding test
  $ hg -R 'a repo' tag tag
  $ hg id --ssh "\"$PYTHON\" \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
  73649e48688a

  $ hg id --ssh "\"$PYTHON\" \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo#noNoNO"
  abort: unknown revision 'noNoNO'!
  [255]

Test (non-)escaping of remote paths with spaces when cloning (issue3145):

  $ hg clone --ssh "\"$PYTHON\" \"$TESTDIR/dummyssh\"" "ssh://user@dummy/a repo"
  destination directory: a repo
  abort: destination 'a repo' is not empty
  [255]

Make sure hg is really paranoid in serve --stdio mode. It used to be
possible to get a debugger REPL by specifying a repo named --debugger.
  $ hg -R --debugger serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--debugger', 'serve', '--stdio']
  [255]
  $ hg -R --config=ui.debugger=yes serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--config=ui.debugger=yes', 'serve', '--stdio']
  [255]
Abbreviations of 'serve' also don't work, to avoid shenanigans.
  $ hg -R narf serv --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', 'narf', 'serv', '--stdio']
  [255]

Test hg-ssh using a helper script that will restore PYTHONPATH (which might
have been cleared by a hg.exe wrapper) and invoke hg-ssh with the right
parameters:

  $ cat > ssh.sh << EOF
  > userhost="\$1"
  > SSH_ORIGINAL_COMMAND="\$2"
  > export SSH_ORIGINAL_COMMAND
  > PYTHONPATH="$PYTHONPATH"
  > export PYTHONPATH
  > "$PYTHON" "$TESTDIR/../contrib/hg-ssh" "$TESTTMP/a repo"
  > EOF

  $ hg id --ssh "sh ssh.sh" "ssh://user@dummy/a repo"
  73649e48688a

  $ hg id --ssh "sh ssh.sh" "ssh://user@dummy/a'repo"
  remote: Illegal repository "$TESTTMP/a'repo"
  abort: no suitable response from remote hg!
  [255]

  $ hg id --ssh "sh ssh.sh" --remotecmd hacking "ssh://user@dummy/a'repo"
  remote: Illegal command "hacking -R 'a'\''repo' serve --stdio"
  abort: no suitable response from remote hg!
  [255]

  $ SSH_ORIGINAL_COMMAND="'hg' -R 'a'repo' serve --stdio" $PYTHON "$TESTDIR/../contrib/hg-ssh"
  Illegal command "'hg' -R 'a'repo' serve --stdio": No closing quotation
  [255]

Test hg-ssh in read-only mode:

  $ cat > ssh.sh << EOF
  > userhost="\$1"
  > SSH_ORIGINAL_COMMAND="\$2"
  > export SSH_ORIGINAL_COMMAND
  > PYTHONPATH="$PYTHONPATH"
  > export PYTHONPATH
  > "$PYTHON" "$TESTDIR/../contrib/hg-ssh" --read-only "$TESTTMP/remote"
  > EOF

  $ hg clone --ssh "sh ssh.sh" "ssh://user@dummy/$TESTTMP/remote" read-only-local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 4 files (+1 heads)
  new changesets 1160648e36ce:1383141674ec
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd read-only-local
  $ echo "baz" > bar
  $ hg ci -A -m "unpushable commit" bar
  $ hg push --ssh "sh ../ssh.sh"
  pushing to ssh://user@dummy/*/remote (glob)
  searching for changes
  remote: Permission denied
  remote: pretxnopen.hg-ssh hook failed
  abort: push failed on remote
  [255]

  $ cd ..

stderr from remote commands should be printed before stdout from local code (issue4336)

  $ hg clone remote stderr-ordering
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd stderr-ordering
  $ cat >> localwrite.py << EOF
  > from mercurial import exchange, extensions
  > 
  > def wrappedpush(orig, repo, *args, **kwargs):
  >     res = orig(repo, *args, **kwargs)
  >     repo.ui.write('local stdout\n')
  >     return res
  > 
  > def extsetup(ui):
  >     extensions.wrapfunction(exchange, 'push', wrappedpush)
  > EOF

  $ cat >> .hg/hgrc << EOF
  > [paths]
  > default-push = ssh://user@dummy/remote
  > [ui]
  > ssh = "$PYTHON" "$TESTDIR/dummyssh"
  > [extensions]
  > localwrite = localwrite.py
  > EOF

  $ echo localwrite > foo
  $ hg commit -m 'testing localwrite'
  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: KABOOM
  remote: KABOOM IN PROCESS
  local stdout

debug output

  $ hg pull --debug ssh://user@dummy/remote --config devel.debug.peer-request=yes
  pulling from ssh://user@dummy/remote
  running .* ".*/dummyssh" ['"]user@dummy['"] ('|")hg -R remote serve --stdio('|") (re)
  sending upgrade request: * proto=exp-ssh-v2-0001 (glob) (sshv2 !)
  devel-peer-request: hello
  sending hello command
  devel-peer-request: between
  devel-peer-request:   pairs: 81 bytes
  sending between command
  remote: 413 (sshv1 !)
  protocol upgraded to exp-ssh-v2-0001 (sshv2 !)
  remote: capabilities: batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset getbundle known lookup protocaps pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
  remote: 1 (sshv1 !)
  devel-peer-request: protocaps
  devel-peer-request:   caps: * bytes (glob)
  sending protocaps command
  query 1; heads
  devel-peer-request: batched-content
  devel-peer-request:    - heads (0 arguments)
  devel-peer-request:    - known (1 arguments)
  devel-peer-request: batch
  devel-peer-request:   cmds: 141 bytes
  sending batch command
  searching for changes
  all remote heads known locally
  no changes found
  devel-peer-request: getbundle
  devel-peer-request:   bookmarks: 1 bytes
  devel-peer-request:   bundlecaps: 266 bytes
  devel-peer-request:   cg: 1 bytes
  devel-peer-request:   common: 122 bytes
  devel-peer-request:   heads: 122 bytes
  devel-peer-request:   listkeys: 9 bytes
  devel-peer-request:   phases: 1 bytes
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "bookmarks" supported
  bundle2-input-part: total payload size 26
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-part: total payload size 45
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 72
  bundle2-input-bundle: 2 parts total
  checking for updated bookmarks

  $ cd ..

  $ cat dummylog
  Got arguments 1:user@dummy 2:hg -R nonexistent serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/nonexistent serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R local-stream serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R doesnotexist serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R local serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/local serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=a28a9d1a809cab7d4e2fde4bee738a9ede948b60 HG_NODE_LAST=a28a9d1a809cab7d4e2fde4bee738a9ede948b60 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:ssh:$LOCALIP
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=1383141674ec756a6056f6a9097618482fe0f4a6 HG_NODE_LAST=1383141674ec756a6056f6a9097618482fe0f4a6 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:ssh:$LOCALIP
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg init 'a repo'
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=65c38f4125f9602c8db4af56530cc221d93b8ef8 HG_NODE_LAST=65c38f4125f9602c8db4af56530cc221d93b8ef8 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:ssh:$LOCALIP
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio

remote hook failure is attributed to remote

  $ cat > $TESTTMP/failhook << EOF
  > def hook(ui, repo, **kwargs):
  >     ui.write('hook failure!\n')
  >     ui.flush()
  >     return 1
  > EOF

  $ echo "pretxnchangegroup.fail = python:$TESTTMP/failhook:hook" >> remote/.hg/hgrc

  $ hg -q --config ui.ssh="\"$PYTHON\" $TESTDIR/dummyssh" clone ssh://user@dummy/remote hookout
  $ cd hookout
  $ touch hookfailure
  $ hg -q commit -A -m 'remote hook failure'
  $ hg --config ui.ssh="\"$PYTHON\" $TESTDIR/dummyssh" push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: hook failure!
  remote: transaction abort!
  remote: rollback completed
  remote: pretxnchangegroup.fail hook failed
  abort: push failed on remote
  [255]

abort during pull is properly reported as such

  $ echo morefoo >> ../remote/foo
  $ hg -R ../remote commit --message "more foo to be pulled"
  $ cat >> ../remote/.hg/hgrc << EOF
  > [extensions]
  > crash = ${TESTDIR}/crashgetbundler.py
  > EOF
  $ hg --config ui.ssh="\"$PYTHON\" $TESTDIR/dummyssh" pull
  pulling from ssh://user@dummy/remote
  searching for changes
  remote: abort: this is an exercise
  abort: pull failed on remote
  [255]

abort with no error hint when there is a ssh problem when pulling

  $ hg pull ssh://brokenrepository -e "\"$PYTHON\" \"$TESTDIR/dummyssh\""
  pulling from ssh://brokenrepository/
  abort: no suitable response from remote hg!
  [255]

abort with configured error hint when there is a ssh problem when pulling

  $ hg pull ssh://brokenrepository -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" \
  > --config ui.ssherrorhint="Please see http://company/internalwiki/ssh.html"
  pulling from ssh://brokenrepository/
  abort: no suitable response from remote hg!
  (Please see http://company/internalwiki/ssh.html)
  [255]

test that custom environment is passed down to ssh executable
  $ cat >>dumpenv <<EOF
  > #! /bin/sh
  > echo \$VAR >&2
  > EOF
  $ chmod +x dumpenv
  $ hg pull ssh://something --config ui.ssh="sh dumpenv"
  pulling from ssh://something/
  remote: 
  abort: no suitable response from remote hg!
  [255]
  $ hg pull ssh://something --config ui.ssh="sh dumpenv" --config sshenv.VAR=17
  pulling from ssh://something/
  remote: 17
  abort: no suitable response from remote hg!
  [255]