extensions: refuse to load extensions if minimum hg version not met
As the author of several 3rd party extensions, I frequently see bug
reports from users attempting to run my extension with an old version
of Mercurial that I no longer support in my extension. Oftentimes, the
extension will import just fine. But as soon as we run extsetup(),
reposetup(), or get into the guts of a wrapped function, we encounter
an exception and abort. Today, Mercurial will print a message about
extensions that don't have a "testedwith" declaring explicit
compatibility with the current version.
The existing mechanism is a good start. But it isn't as robust as I
would like. Specifically, Mercurial assumes compatibility by default.
This means extension authors must perform compatibility checking in
their extsetup() or we wait and see if we encounter an abort at
runtime. And, compatibility checking can involve a lot of code and
lots of error checking. It's a lot of effort for extension authors.
Oftentimes, extension authors know which versions of Mercurial there
extension works on and more importantly where it is broken.
This patch introduces a magic "minimumhgversion" attribute in
extensions. When found, the extension loading mechanism will compare
the declared version against the current Mercurial version. If the
extension explicitly states we require a newer Mercurial version, a
warning is printed and the extension isn't loaded beyond importing
the Python module. This causes a graceful failure while alerting
the user of the compatibility issue.
I would be receptive to the idea of making the failure more fatal.
However, care would need to be taken to not criple every hg command.
e.g. the user may use `hg config` to fix the hgrc and if we aborted
trying to run that, the user would effectively be locked out of `hg`!
A potential future improvement to this functionality would be to catch
ImportError for the extension/module and parse the source code for
"minimumhgversion = 'XXX'" and do similar checking. This way we could
give more information about why the extension failed to load.
Check that obsolete properly strip heads
$ cat >> $HGRCPATH << EOF
> [phases]
> # public changeset are not obsolete
> publish=false
> [ui]
> logtemplate='{node|short} ({phase}) {desc|firstline}\n'
> [experimental]
> evolution=createmarkers
> EOF
$ mkcommit() {
> echo "$1" > "$1"
> hg add "$1"
> hg ci -m "add $1"
> }
$ getid() {
> hg id --debug -ir "desc('$1')"
> }
$ hg init remote
$ cd remote
$ mkcommit base
$ hg phase --public .
$ cd ..
$ cp -r remote base
$ hg clone remote local
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local
New head replaces old head
==========================
setup
(we add the 1 flags to prevent bumped error during the test)
$ mkcommit old
$ hg push
pushing to $TESTTMP/remote (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
$ hg up -q '.^'
$ mkcommit new
created new head
$ hg debugobsolete --flags 1 `getid old` `getid new`
$ hg log -G --hidden
@ 71e3228bffe1 (draft) add new
|
| x c70b08862e08 (draft) add old
|/
o b4952fcf48cf (public) add base
$ cp -r ../remote ../backup1
old exists remotely as draft. It is obsoleted by new that we now push.
Push should not warn about creating new head
$ hg push
pushing to $TESTTMP/remote (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
old head is now public (public local version)
=============================================
setup
$ rm -fr ../remote
$ cp -r ../backup1 ../remote
$ hg -R ../remote phase --public c70b08862e08
$ hg pull -v
pulling from $TESTTMP/remote (glob)
searching for changes
no changes found
$ hg log -G --hidden
@ 71e3228bffe1 (draft) add new
|
| o c70b08862e08 (public) add old
|/
o b4952fcf48cf (public) add base
Abort: old will still be an head because it's public.
$ hg push
pushing to $TESTTMP/remote (glob)
searching for changes
abort: push creates new remote head 71e3228bffe1!
(merge or see "hg help push" for details about pushing new heads)
[255]
old head is now public (public remote version)
==============================================
TODO: Not implemented yet.
# setup
#
# $ rm -fr ../remote
# $ cp -r ../backup1 ../remote
# $ hg -R ../remote phase --public c70b08862e08
# $ hg phase --draft --force c70b08862e08
# $ hg log -G --hidden
# @ 71e3228bffe1 (draft) add new
# |
# | x c70b08862e08 (draft) add old
# |/
# o b4952fcf48cf (public) add base
#
#
#
# Abort: old will still be an head because it's public.
#
# $ hg push
# pushing to $TESTTMP/remote
# searching for changes
# abort: push creates new remote head 71e3228bffe1!
# (merge or see "hg help push" for details about pushing new heads)
# [255]
old head is obsolete but replacement is not pushed
==================================================
setup
$ rm -fr ../remote
$ cp -r ../backup1 ../remote
$ hg phase --draft --force '(0::) - 0'
$ hg up -q '.^'
$ mkcommit other
created new head
$ hg log -G --hidden
@ d7d41ccbd4de (draft) add other
|
| o 71e3228bffe1 (draft) add new
|/
| x c70b08862e08 (draft) add old
|/
o b4952fcf48cf (public) add base
old exists remotely as draft. It is obsoleted by new but we don't push new.
Push should abort on new head
$ hg push -r 'desc("other")'
pushing to $TESTTMP/remote (glob)
searching for changes
abort: push creates new remote head d7d41ccbd4de!
(merge or see "hg help push" for details about pushing new heads)
[255]
Both precursors and successors are already know remotely. Descendant adds heads
===============================================================================
setup. (The obsolete marker is known locally only
$ cd ..
$ rm -rf local
$ hg clone remote local
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local
$ mkcommit old
old already tracked!
nothing changed
[1]
$ hg up -q '.^'
$ mkcommit new
created new head
$ hg push -f
pushing to $TESTTMP/remote (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
$ mkcommit desc1
$ hg up -q '.^'
$ mkcommit desc2
created new head
$ hg debugobsolete `getid old` `getid new`
$ hg log -G --hidden
@ 5fe37041cc2b (draft) add desc2
|
| o a3ef1d111c5f (draft) add desc1
|/
o 71e3228bffe1 (draft) add new
|
| x c70b08862e08 (draft) add old
|/
o b4952fcf48cf (public) add base
$ hg log -G --hidden -R ../remote
o 71e3228bffe1 (draft) add new
|
| o c70b08862e08 (draft) add old
|/
@ b4952fcf48cf (public) add base
$ cp -r ../remote ../backup2
Push should not warn about adding new heads. We create one, but we'll delete
one anyway.
$ hg push
pushing to $TESTTMP/remote (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files (+1 heads)
Remote head is unknown but obsoleted by a local changeset
=========================================================
setup
$ rm -fr ../remote
$ cp -r ../backup1 ../remote
$ cd ..
$ rm -rf local
$ hg clone remote local -r 0
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd local
$ mkcommit new
$ hg -R ../remote id --debug -r tip
c70b08862e0838ea6d7c59c85da2f1ed6c8d67da tip
$ hg id --debug -r tip
71e3228bffe1886550777233d6c97bb5a6b2a650 tip
$ hg debugobsolete c70b08862e0838ea6d7c59c85da2f1ed6c8d67da 71e3228bffe1886550777233d6c97bb5a6b2a650
$ hg log -G --hidden
@ 71e3228bffe1 (draft) add new
|
o b4952fcf48cf (public) add base
$ hg log -G --hidden -R ../remote
o c70b08862e08 (draft) add old
|
@ b4952fcf48cf (public) add base
Push should not complain about new heads.
$ hg push --traceback
pushing to $TESTTMP/remote (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)