Thomas Keller <m...@thomaskeller.biz> writes: > Am 05.05.10 09:13, schrieb Stephen Leake: >> Stephen Leake <stephen_le...@stephe-leake.org> writes: >> >>> Stephen Leake <stephen_le...@stephe-leake.org> writes: >>> >>>> Mando Rodriguez <mandorodrig...@gmail.com> writes: >>>> >>>>> When attempting to perform a merge we get this : >>>>> >>>>> / >>>>> mtn: 2 heads on branch '0' >>>>> mtn: merge 1 / 1: >>>>> mtn: calculating best pair of heads to merge next >>>>> mtn: [left] 1d8d9ecda9ed7bd5b34dfbb48d4ce0d61e071598 >>>>> mtn: [right] 96c815a1768eb25e49bf74ba3d6e6236adefb30a >>>>> mtn: fatal: error: roster.cc:1826: >>>>> I(left_uncommon_ancestors.find(left_rid) != >>>>> left_uncommon_ancestors.end()) >>>>> mtn: this is almost certainly a bug in monotone. >>>> >>>> I may have time to look at it this weekend. >>> >>> I finally started looking into this. >>> >>> The immediate cause of the crash is an invariant failure in >>> roster.cc:2066 make_roster_for_merge: >>> >>> I(left_uncommon_ancestors.find(left_rid) != left_uncommon_ancestors.end()); >>> >>> I rearranged the MM and I lines there so left_uncommon_ancestors would >>> be dumped on --debug, and it is empty. >>> >>> ... >> >> I've made some more progress. The database is inconsistent; the table >> "branch_leaves" has incorrect entries. I can't reproduce the error, but >> the fix is simple; run database::recalc_branch_leaves. > > As far as I remember this table is quite new and was added by Tim last > November to speed up certain things - maybe it would be a good idea if > he could have a look into the issue as well...? > >> I added 'mtn db recalc_branch_heads' (not committed), and after running >> it, 'mtn heads' correctly shows just one head. >> >> We could add a check for this to 'mtn db check'; it could compute the >> branch leaves and compare to the current values in the branch_leaves table. >> >> If no one objects, I'll check in the 'db recalc_branch_heads' command, >> and work on a new check in 'db check'. > > The check is definitely a good idea -
Ok. > if we want a separate recalc_branch_heads command is questionable - > for two reasons: > > 1) I fear we fix something whose original cause we still haven't > understood - as you correctly stated in one of your previous mails > "Before we discuss committing that change, we need to understand why mtn > thinks this graph has two heads, and how it got that way." Ok. But we need some workaround to fix the problem until we do find the real cause. > 2) If we cannot track the problem down and find any other way than > regenerating the branch leave cache to fix the problem, then I'd propose > we call recalc_branch_leaves as part of the `db regenerate_caches` > command (if it doesn't take so long to additionally recalculate them). That makes sense; "branch_leaves" is a cache, and if one cache is broken, it's likely others are. It took a noticable but not significant time to run 'recalc_branch_heads', but there's no reason not to include it in regenerate_caches. -- -- Stephe _______________________________________________ Monotone-devel mailing list Monotone-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/monotone-devel
