[TRAC] Hitting assertion in threaded cbc run inside ClpSimplexDual

[bernalde]

Moved from TRAC as part of COIN fORgery: https://projects.coin-or.org/Clp/ticket/81

Dear all,

currently I try to test the Cbc solver as an replacement of mine old (commercial) MIP solver. A set of optimizations are done in row (always the same layout, but a different setup, using the Cbc threading feature), but currently I hit the following assertion in the ClpSimplexDual? Method (that's why I post it to the Clp page):

ClpSimplexDual?.cpp:2403: int ClpSimplexDual::updateDualsInDual(CoinIndexed? Vector*, CoinIndexedVector?*, CoinIndexedVector?*, double, double&, bool): Assertion iStatus>0' failed.`

What's the reason to hit this assertion? Is there a way to fix this assertion on the Clp site or must the reason be fixed from the user point of view?

I use the the current stable branch.

Thank you very much for your help.

[multipitch]

Hi bernalde, I've just encoutnered the same error. It seems that there hasn't been a release of CLP in over a year (last release was June 2017). Line 2403 of ClpSimplexDual.cpp in that release is as follows:
assert (iStatus>0);
So I assume something is making this assertion fail.
This must have been due to some bug as the behaviour has been changed in a more recent commit.
I guess the only solution is to build Clp from source until the next release comes along (I'll be trying this myself at some stage and will let you know how it goes).
Note I know very little about the source (or C++ in general) so I don't really understand what the buggy function is doing / should be doing.

[tkralphs]

A new release is coming soon, but in the meantime, there are automatically built binaries of the latest trunk, which should be patched and work well, for all platforms .

https://bintray.com/coin-or/download/Clp/trunk

The release, when it comes, will be more or less this version. GIve it a try and feel free to report if there are still issues.