wireprotov2: change how revisions are specified to changesetdata
Right now, we have a handful of arguments for specifying the revisions
whose data should be returned. Defining how all these arguments
interact when various combinations are present is difficult.
This commit establishes a new, generic mechanism for specifying
revisions. Instead of a hodgepodge of arguments defining things, we
have a list of dicts that specify revision selectors. The final set
of revisions is a union of all these selectors.
We implement support for specifying revisions based on:
* An explicit list of changeset revisions
* An explicit list of changeset revisions plus ancestry depth
* A DAG range between changeset roots and heads
If you squint hard enough, this problem has already been solved by
revsets. But I'm reluctant to expose revsets to the wire protocol
because that would require servers to implement a revset parser.
Plus there are security and performance implications: the set
of revision selectors needs to be narrowly and specifically tailored
for what is appropriate to be executing on a server. Perhaps there
would be a way for us to express the "parse tree" of a revset
query, for example. I'm not sure. We can explore this space another
time. For now, the new mechanism should bring sufficient flexibility
while remaining relatively simple.
The selector "types" are prefixed with "changeset" because I plan
to add manifest and file-flavored selectors as well. This will enable
us to e.g. select file revisions based on a range of changeset
revisions.
Differential Revision: https://phab.mercurial-scm.org/D4979
#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
8 files to transfer, 827 bytes of data
transferred 827 bytes in * seconds (*) (glob)
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
checked 3 changesets with 2 changes to 2 files
$ 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
9 files to transfer, 870 bytes of data
transferred 870 bytes in * seconds (*) (glob)
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
checked 3 changesets with 2 changes to 2 files
$ 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
checked 4 changesets with 3 changes to 2 files
$ 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 --config paths.default=bogus://invalid --config paths.default:pushurl=`hg paths default`
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")
> sys.stdout.flush()
> EOF
$ cat <<EOF > $TESTTMP/badpyhook.py
> import sys
> def hook(ui, repo, hooktype, **kwargs):
> sys.stdout.write("KABOOM IN PROCESS\n")
> sys.stdout.flush()
> 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
#if chg
try again with remote chg, which should succeed as well
$ hg rollback -R ../remote
repository tip rolled back to revision 4 (undo serve)
$ hg push --config ui.remotecmd=chg
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
#endif
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(b'local stdout\n')
> repo.ui.flush()
> return res
>
> def extsetup(ui):
> extensions.wrapfunction(exchange, b'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-v2-0003 (glob) (sshv2 !)
devel-peer-request: hello+between
devel-peer-request: pairs: 81 bytes
sending hello command
sending between command
remote: 427 (sshv1 !)
protocol upgraded to exp-ssh-v2-0003 (sshv2 !)
remote: capabilities: batch branchmap $USUAL_BUNDLE2_CAPS$ 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:$LOCALIP
Got arguments 1:user@dummy 2:chg -R remote serve --stdio (chg !)
changegroup-in-remote hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=1383141674ec756a6056f6a9097618482fe0f4a6 HG_NODE_LAST=1383141674ec756a6056f6a9097618482fe0f4a6 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:ssh:$LOCALIP (chg !)
Got arguments 1:user@dummy 2:hg -R remote serve --stdio
Got arguments 1:user@dummy 2:hg init 'a repo'
Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
Got arguments 1:user@dummy 2:hg -R remote serve --stdio
changegroup-in-remote hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=65c38f4125f9602c8db4af56530cc221d93b8ef8 HG_NODE_LAST=65c38f4125f9602c8db4af56530cc221d93b8ef8 HG_SOURCE=serve HG_TXNID=TXN:$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(b'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]