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.
$ hg init test
$ cd test
$ hg unbundle "$TESTDIR/bundles/remote.hg"
adding changesets
adding manifests
adding file changes
added 9 changesets with 7 changes to 4 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ..
$ for i in 0 1 2 3 4 5 6 7 8; do
> mkdir test-"$i"
> hg --cwd test-"$i" init
> hg -R test bundle -r "$i" test-"$i".hg test-"$i"
> cd test-"$i"
> hg unbundle ../test-"$i".hg
> hg verify
> hg tip -q
> cd ..
> done
searching for changes
1 changesets found
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
0:bfaf4b5cbf01
searching for changes
2 changesets found
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
1:21f32785131f
searching for changes
3 changesets found
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
2:4ce51a113780
searching for changes
4 changesets found
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 4 changesets, 4 total revisions
3:93ee6ab32777
searching for changes
2 changesets found
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
1:c70afb1ee985
searching for changes
3 changesets found
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
2:f03ae5a9b979
searching for changes
4 changesets found
adding changesets
adding manifests
adding file changes
added 4 changesets with 5 changes to 2 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 4 changesets, 5 total revisions
3:095cb14b1b4d
searching for changes
5 changesets found
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 3 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 5 changesets, 6 total revisions
4:faa2e4234c7a
searching for changes
5 changesets found
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 5 changesets, 5 total revisions
4:916f1afdef90
$ cd test-8
$ hg pull ../test-7
pulling from ../test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 2 changes to 3 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions
$ hg rollback
repository tip rolled back to revision 4 (undo pull)
$ cd ..
should fail
$ hg -R test bundle --base 2 -r tip test-bundle-branch1.hg test-3
abort: --base is incompatible with specifying a destination
[255]
$ hg -R test bundle -r tip test-bundle-branch1.hg
abort: repository default-push not found!
[255]
$ hg -R test bundle --base 2 -r tip test-bundle-branch1.hg
2 changesets found
$ hg -R test bundle --base 2 -r 7 test-bundle-branch2.hg
4 changesets found
$ hg -R test bundle --base 2 test-bundle-all.hg
6 changesets found
$ hg -R test bundle --base 3 -r tip test-bundle-should-fail.hg
1 changesets found
empty bundle
$ hg -R test bundle --base 7 --base 8 test-bundle-empty.hg
no changes found
[1]
issue76 msg2163
$ hg -R test bundle --base 3 -r 3 -r 3 test-bundle-cset-3.hg
no changes found
[1]
Issue1910: 'hg bundle --base $head' does not exclude $head from
result
$ hg -R test bundle --base 7 test-bundle-cset-7.hg
4 changesets found
$ hg clone test-2 test-9
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd test-9
revision 2
$ hg tip -q
2:4ce51a113780
$ hg unbundle ../test-bundle-should-fail.hg
adding changesets
transaction abort!
rollback completed
abort: 00changelog.i@93ee6ab32777: unknown parent!
[255]
revision 2
$ hg tip -q
2:4ce51a113780
$ hg unbundle ../test-bundle-all.hg
adding changesets
adding manifests
adding file changes
added 6 changesets with 4 changes to 4 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
revision 8
$ hg tip -q
8:916f1afdef90
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions
$ hg rollback
repository tip rolled back to revision 2 (undo unbundle)
revision 2
$ hg tip -q
2:4ce51a113780
$ hg unbundle ../test-bundle-branch1.hg
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
(run 'hg update' to get a working copy)
revision 4
$ hg tip -q
4:916f1afdef90
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 5 changesets, 5 total revisions
$ hg rollback
repository tip rolled back to revision 2 (undo unbundle)
$ hg unbundle ../test-bundle-branch2.hg
adding changesets
adding manifests
adding file changes
added 4 changesets with 3 changes to 3 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
revision 6
$ hg tip -q
6:faa2e4234c7a
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 7 changesets, 6 total revisions
$ hg rollback
repository tip rolled back to revision 2 (undo unbundle)
$ hg unbundle ../test-bundle-cset-7.hg
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
(run 'hg update' to get a working copy)
revision 4
$ hg tip -q
4:916f1afdef90
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 5 changesets, 5 total revisions
$ cd ../test
$ hg merge 7
note: possible conflict - afile was renamed multiple times to:
anotherfile
adifferentfile
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m merge
$ cd ..
$ hg -R test bundle --base 2 test-bundle-head.hg
7 changesets found
$ hg clone test-2 test-10
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd test-10
$ hg unbundle ../test-bundle-head.hg
adding changesets
adding manifests
adding file changes
added 7 changesets with 4 changes to 4 files
(run 'hg update' to get a working copy)
revision 9
$ hg tip -q
9:03fc0b0e347c
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 10 changesets, 7 total revisions
$ cd ..