# Build suddenly starting to error out - unmet package dependencies

**URL:** <https://travis-ci.community/t/build-suddenly-starting-to-error-out-unmet-package-dependencies/8182>\
**Category:** Linux\
**Created:** [April 16, 2020, 7:45pm UTC](https://travis-ci.community/t/build-suddenly-starting-to-error-out-unmet-package-dependencies/8182 "2020-04-16T19:45:06Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![native-api](https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/native-api/32/430_2.png) [@native-api](https://travis-ci.community/u/native-api)\
**Post date:** [April 16, 2020, 9:07pm UTC](https://travis-ci.community/t/build-suddenly-starting-to-error-out-unmet-package-dependencies/8182/5 "2020-04-16T21:07:17Z")

</div>

Run the same `apt` invocation manually, adding `-o Debug::pkgProblemResolver=yes` to it.

This will show which packages are conflicting with those that you are installing.

Usually, this error means that some of the preinstalled conflicting dependency packages have been installed manually and as such, they aren’t being replaced automatically unless you explicitly specify a corresponding replacement dependency.

E.g. this has happened before in

> [@Failures installing MariaDB 10.2 on Xenial](https://travis-ci.community/t/failures-installing-mariadb-10-2-on-xenial/5284/4):
>
> Okay, I found the cause of the discrepancy. In Xenial, [all 4 MySQL packages are marked as manually installed](https://travis-ci.org/native-api/test_travis/builds/593803507#L602-L606). So [I’d have to supply all the 4 corresponding MariaDB packages on the command line manually, too,](https://travis-ci.org/native-api/test_travis/builds/593807343#L221) for them to override the MySQL ones. @BanzaiMan I could make a workaround PR so that MariaDB addon starts working in Xenial+ before [https://github.com/travis-ci/travis-cookbooks/pull/1057](https://github.com/travis-ci/travis-cookbooks/pull/1057) is deployed. But I would rather help you resolve whatever problem you are having with updating VM …

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