Mercurial > hg
view CONTRIBUTORS @ 27142:060f83d219b9
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.
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Tue, 24 Nov 2015 15:16:25 -0800 |
parents | c29efd272395 |
children |
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[This file is here for historical purposes, all recent contributors should appear in the changelog directly] Andrea Arcangeli <andrea at suse.de> Thomas Arendsen Hein <thomas at intevation.de> Goffredo Baroncelli <kreijack at libero.it> Muli Ben-Yehuda <mulix at mulix.org> Mikael Berthe <mikael at lilotux.net> Benoit Boissinot <bboissin at gmail.com> Brendan Cully <brendan at kublai.com> Vincent Danjean <vdanjean.ml at free.fr> Jake Edge <jake at edge2.net> Michael Fetterman <michael.fetterman at intel.com> Edouard Gomez <ed.gomez at free.fr> Eric Hopper <hopper at omnifarious.org> Alecs King <alecsk at gmail.com> Volker Kleinfeld <Volker.Kleinfeld at gmx.de> Vadim Lebedev <vadim at mbdsys.com> Christopher Li <hg at chrisli.org> Chris Mason <mason at suse.com> Colin McMillen <mcmillen at cs.cmu.edu> Wojciech Milkowski <wmilkowski at interia.pl> Chad Netzer <chad.netzer at gmail.com> Bryan O'Sullivan <bos at serpentine.com> Vicent SeguĂ Pascual <vseguip at gmail.com> Sean Perry <shaleh at speakeasy.net> Nguyen Anh Quynh <aquynh at gmail.com> Ollivier Robert <roberto at keltia.freenix.fr> Alexander Schremmer <alex at alexanderweb.de> Arun Sharma <arun at sharma-home.net> Josef "Jeff" Sipek <jeffpc at optonline.net> Kevin Smith <yarcs at qualitycode.com> TK Soh <teekaysoh at yahoo.com> Radoslaw Szkodzinski <astralstorm at gorzow.mm.pl> Samuel Tardieu <sam at rfc1149.net> K Thananchayan <thananck at yahoo.com> Andrew Thompson <andrewkt at aktzero.com> Michael S. Tsirkin <mst at mellanox.co.il> Rafael Villar Burke <pachi at mmn-arquitectos.com> Tristan Wibberley <tristan at wibberley.org> Mark Williamson <mark.williamson at cl.cam.ac.uk>